You are here

Selection from American Military History-The U.S. Army in Vietnam, 1989

Chapter 28, The U.S. Army in Vietnam by Vincent H. Demma
January 1, 1989
Print

From: AMERICAN MILITARY HISTORY, Center of Military History, United States Army, Washington, D.C., 1989

Chapter 28, THE U.S. ARMY IN VIETNAM, by Vincent H. Demma

The Vietnam War was the legacy of France's failure to suppress nationalist forces in Indochina as it struggled to restore its colonial dominion after World War II. Led by Ho Chi Minh, a Communist-dominated revolutionary movement-the Viet Minh-waged a political and military struggle for Vietnamese independence that frustrated the efforts of the French and resulted ultimately in their ouster from the region.

The U.S. Army's first encounters with Ho Chi Minh were brief and sympathetic. During World War II, Ho's anti-Japanese resistance fighters helped to rescue downed American pilots and furnished information on Japanese forces in Indochina. U.S. Army officers stood at Ho's side in August 1945 as he basked in the short-lived satisfaction of declaring Vietnam's independence. Five years later, however, in an international climate tense with ideological and military confrontation between Communist and non-Communist powers, Army advisers of the newly formed U.S. Military Assistance Advisory Group (MAAG), Indochina, were aiding France against the Viet Minh. With combat raging in Korea and mainland China recently fallen to the Communists, the war in Indochina now appeared to Americans as one more pressure point to be contained on a wide arc of Communist expansion in Asia. By underwriting French military efforts in Southeast Asia, the United States enabled France to sustain its economic recovery and to contribute, through the North Atlantic Treaty Organization (NATO), to the collective defense of western Europe.

Provided with aircraft, artillery, tanks, vehicles, weapons, and other equipment and supplies-a small portion of which they distributed to an anti-Communist Vietnamese army they had organized-the French did not fail for want of equipment. Instead, they put American aid at the service of a flawed strategy that sought to defeat the elusive Viet Minh in set- piece battles, but neglected to cultivate the loyalty and support of the Vietnamese people. Too few in number to provide more than a veneer of security in most rural areas, the French were unable to suppress the guerrillas or to prevent the underground Communist shadow government from reappearing whenever French forces left one area to fight elsewhere.

The battle of Dien Bien Phu epitomized the shortcomings of French strategy. Located near the Laotian border in a rugged valley of remote northwestern Vietnam, Dien Bien Phu was not a congenial place to fight. Far inland from coastal supply bases and with roads vulnerable to the Viet Minh, the base depended almost entirely on air support. The French, expecting the Viet Minh to invade Laos, occupied Dien Bien Phu in November 1953 in order to force a battle. Yet they had little to gain from an engagement. Victory at Dien Bien Phu would not have ended the war; even if defeated, the Viet Minh would have retired to their mountain redoubts. And no French victory at Dien Bien Phu would have reduced Communist control over large segments of  the population. On the other hand, the French had much to lose, in manpower, equipment, and prestige.

Their position was in a valley, surrounded by high ground that the Viet Minh quickly fortified. While bombarding the besieged garrison with artillery and mortars, the attackers tunneled closer to the French positions. Supply aircraft that successfully ran the gauntlet of intense antiaircraft fire risked destruction on the ground from Viet Minh artillery. Eventually supplies and  ammunition could be delivered to the defenders only by parachute drop As the situation became critical, France asked the United States to intervene. Believing that the French position was untenable and that even massive American air attacks using small nuclear bombs would be futile, General Matthew B. Ridgway, the Army Chief of Staff, helped to convince President Dwight D. Eisenhower not to aid them. Ridgway also opposed the use of U.S. ground forces, arguing that such an effort would severely strain the Army and possibly lead to a wider war in Asia.

The fall of Dien Bien Phu on 7 May 1954, as peace negotiations were about to start in Geneva, hastened France's disengagement from Indochina. On 20 July, France and the Viet Minh agreed to end hostilities and to divide Vietnam temporarily into two zones at the 17th parallel. In the North, the Viet Minh established a Communist government, with its capital at Hanoi. French forces withdrew to the South, and hundreds of thousands of civilians, most of whom were Roman Catholics, accompanied them. The question of unification was left to be decided by an election scheduled for 1956.

The Emergence of South Vietnam

As the Viet Minh consolidated control in the North, Ngo Dinh Diem, a Roman Catholic of mandarin background, sought to assert his authority over the chaotic conditions in the South in hopes of establishing an anti-Communist state. A onetime minister in the French colonial administration Diem enjoyed a reputation for honesty. He had resigned his office in 1933 and had taken no part in the tumultuous events that swept over Vietnam after the war. Diem returned to Saigon in the summer of 1954 as premier with no political following except his family and a few Americans. His authority was challenged, first by the independent Hoa Hao and Cao Dai religious sects and, then by the Binh Xuyen, an organization of gangsters that controlled Saigon's gambling dens and brothels and had strong influence with the police. Rallying an army, Diem defeated the sects and gained their grudging allegiance. Remnants of their forces, however, fled to the jungle to continue their resistance, and some, at a later date, became the nucleus of Communist guerrilla units.

Diem was also challenged by members of his own army, where French influence persisted among the highest ranking officers. But he weathered the threat of an army coup, dispelling American doubts about his ability to survive in the jungle of Vietnamese politics. For the next few years, the United States commitment to defend South Vietnam's independence was synonymous with support for Diem. Americans now provided advice and support to the Army of the Republic of Vietnam (ARVN); at Diem's request, they replaced French advisers throughout his nation's military establishment.

As the American role in South Vietnam was growing, U.S. defense policy was undergoing review. Officials in the Eisenhower administration believed that wars like those in Korea and Vietnam were too costly and ought to be avoided in the future. "Never again" was the rallying cry of those who opposed sending U.S. ground forces to fight a conventional war in Asia. Instead, the Eisenhower administration relied on the threat or use of massive nuclear retaliation to deter or, if necessary, to defeat the armies of the Soviet Union or Communist China. The New Look, as this policy was called, emphasized nuclear air power at the expense of conventional ground forces. If deterrence failed, planners envisioned the next war as a short, violent nuclear conflict of a few days' duration, conducted with forces in being. Ground forces were relegated to a minor role, and mobilization was regarded as an unnecessary luxury. In consequence, the Army's share of the defense budget decreased, the modernization of its forces was delayed, and its strength was reduced by 40 percent-from 1,404,598 in 1954 to 861,964 in 1956.

A strategy dependent on one form of military power, the New Look was sharply criticized by soldiers and academics alike. Unless the United States was willing to risk destruction, critics argued, the threat of massive nuclear retaliation had little credibility. General Ridgway and his successor, General Maxwell D. Taylor, were vocal opponents. Both advocated balanced forces to enable the United States to cope realistically with a variety of military contingencies. The events of the late 1950's appeared to support their demand for flexibility. The United States intervened in Lebanon in 1956 to restore political stability there. Two years later an American military show of force in the Straits of Taiwan helped to dampen tensions between Communist China and the Nationalist Chinese Government on Formosa. Both contingencies underlined the importance of avoiding any fixed concept of war.

Advocates of the flexible response doctrine foresaw a meaningful role for the Army as part of a more credible deterrent and as a means of intervening, when necessary, in limited and small wars. They wished to strengthen both conventional and unconventional forces; to improve strategic and tactical mobility and to maintain troops and equipment at forward bases, close to likely areas of conflict. They placed a premium on highly responsive command and control, to allow a close meshing of military actions with political goals. The same reformers were deeply interested in the conduct of brushfire wars, especially among the underdeveloped nations. In the so-called third world, competing cold war ideologies and festering nationalistic, religious, and social conflicts interacted with the disruptive forces of modernization to create the preconditions for open hostilities. Southeast Asia was one of several such areas identified by the Army. Here the United States' central concern was the threat of North Vietnamese and perhaps Chinese aggression against South Vietnam and other non-Communist states.

The United States took the lead in forming a regional defense pact, the Southeast Asia Treaty Organization (SEATO), signaling its commitment to contain Communist encroachment in the region. Meanwhile the 342 American advisers of MAAG, Vietnam (which replaced MAAG, Indochina, in 1955), trained and organized Diem's fledgling army to resist an invasion from the North. Three MAAG chiefs-Lt. Gens. John W. O'Daniel, Samuel T Williams, and Lionel C. McGarr-reorganized South Vietnam's light mobile infantry groups into infantry divisions, compatible in design and mission with U.S. defense plans. The South Vietnamese Army, with a strength of about 150,000, was equipped with standard Army equipment and given the mission of delaying the advance of any invasion force until the arrival of American reinforcements. The residual influence of the army's earlier French training, however, lingered in both leadership and tactics. The South Vietnamese had little or no practical experience in administration and the higher staff functions, from which the French had excluded them.

The MAAG's training and reorganization work was often interrupted by Diem's use of his army to conduct "pacification" campaigns to root out stay-behind Viet Minh cadre. Hence responsibility for most internal security was transferred to poorly trained and ill-equipped paramilitary forces, the Civil Guard and Self-Defense Corps, which numbered about 75,000. For the most part, the Viet Minh in the South avoided armed action and subscribed to a political action program in anticipation of Vietnam-wide elections in 1956, as stipulated by the Geneva Accords. But Diem, supported by the United States, refused to hold elections, claiming that undemocratic conditions in the North precluded a fair contest. (Some observers thought Ho Chi Minh sufficiently popular in the South to defeat Diem.) Buoyed by his own election as President in 1955 and by the adulation of his American supporters, Diem's political strength rose to its apex. While making some political and economic reforms, he pressed hard his attacks on political opponents and former Viet Minh, many of whom were not Communists at all but patriots who had joined the movement to fight for Vietnamese  independence.

By 1957 Diem's harsh measures had so weakened the Viet Minh that Communist leaders in the South feared for the movement's survival there. The southerners urged their colleagues in the North to sanction a new armed struggle in South Vietnam. For self-protection, some Viet Minh had fled to secret bases to hide and form small units. Others joined renegade elements of the former sect armies. From bases in the mangrove swamps of the Mekong Delta, in the Plain of Reeds near the Cambodian border, and in the jungle of War Zones C and D northwest of Saigon, the Communists began to rebuild their armed forces, to re-establish an underground political network, and to carry out propaganda, harassment, and terrorist activities. As reforms faltered and Diem became more dictatorial, the ranks of the rebels swelled with the politically disaffected.

The Rise of the Viet Cong

The insurgents, now called the Viet Cong, had organized several companies and a few battalions by 1959, the majority in the Delta and the provinces around Saigon. As Viet Cong military strength increased, attacks against the paramilitary forces, and occasionally against the South Vietnamese Army, became more frequent. Many were conducted to obtain equipment, arms, and ammunition, but all were hailed by the guerrillas as evidence of the government's inability to protect its citizens. Political agitation and military activity also quickened in the Central Highlands, where Viet Cong agents recruited among the Montagnard tribes. In 1959, after assessing conditions in the South, the leaders in Hanoi agreed to resume the armed struggle, giving it equal weight with political efforts to undermine Diem and reunify Vietnam. To attract the growing number of anti-Communists opposed to Diem, as well as to provide a democratic facade for administering the party's policies in areas controlled by the Viet Cong, Hanoi in December 1960 created the National Liberation Front of South Vietnam. The revival of guerrilla warfare in the South found the advisory group, the South Vietnamese Army, and Diem's government ill prepared to wage an effective campaign. In their efforts to train and strengthen Diem's army, U.S. advisers had concentrated on meeting the threat of a conventional North Vietnamese invasion. The ARVN's earlier antiguerrilla campaigns, while seemingly successful, had been carried out against a weak and dormant insurgency. The Civil Guard and Self-Defense Corps, which bore the brunt of the Viet Cong's attacks, were not under the MAAG's purview and proved unable to cope with the audacious Viet Cong. Diem's regime, while stressing military activities, neglected political, social, and economic reforms. American officials disagreed over the seriousness of the guerrilla threat, the priority to be accorded political or military measures, and the need for special counterguerrilla training for the South Vietnamese Army. Only a handful of the MAAG's advisers had personal experience in counterinsurgency warfare.

Yet the U.S. Army was not a stranger to such conflict. Americans had fought insurgents in the Philippines at the turn of the century, conducted a guerrilla campaign in Burma during World War II, helped the Greek and Philippine Governments to subdue Communist insurgencies after the war, and studied the French failure in Indochina and the British success in Malaya. The Army did not, however, have a comprehensive doctrine for dealing with insurgency. For the most part, insurgent warfare was equated with the type of guerrilla or partisan struggles carried out during World War II behind enemy lines in support of conventional operations. This viewpoint reduced antiguerrilla warfare to providing security against enemy partisans operating behind friendly lines.

Almost totally lacking was an appreciation of the political and social dimensions of insurgency and its role in the larger framework of revolutionary war. Insurgency meant above all a contest for political legitimacy and power-a struggle between contending political cultures over the organization of society. Most of the Army advisers and Special Forces who were sent to South Vietnam in the early 1960's were poorly prepared to wage such a struggle A victory for counterinsurgency in South Vietnam would require Diem's government not only to outfight the guerrillas, but to compete successfully with their efforts to organize the population in support of the government's cause.

The Viet Cong thrived on their access to and control of the people, who formed the most important part of their support base. The population provided both economic and manpower resources to sustain and expand the insurgency; the people of the villages served the guerrillas as their first line of resistance against government intrusion into their "liberated zones" and bases. By comparison with their political effort, the strictly military aims of the Viet Cong were secondary. The insurgents hoped not to destroy government forces-although they did so when weaker elements could be isolated and defeated-but by limited actions to extend their influence over the population. By mobilizing the population, the Viet Cong compensated for their numerical and material disadvantages. The rule of thumb that ten soldiers were needed to defeat one guerrilla reflected the insurgents' political support rather than their military superiority. For the Saigon government, the task of isolating the Viet Cong from the population was difficult under any circumstances and impossible to achieve by force alone.

Viet Cong military forces varied from hamlet and village guerrillas, who were farmers by day and fighters by night, to full-time professional soldiers. Organized into squads and platoons, part-time guerrillas had several military functions. They gathered intelligence, passing it on to district or provincial authorities; they proselytized, propagandized, recruited, and provided security for local cadres. They reconnoitered the battlefield, served as porters and guides, created diversions, evacuated wounded, and retrieved weapons. Their very presence and watchfulness in a hamlet or village inhibited the population from aiding the government.

By contrast, the local and main force units consisted of full-time soldiers, most often recruited from the area where the unit operated. Forming companies and battalions, local forces were attached to a village, district, or provincial headquarters. Often they formed the protective shield behind which a Communist Party cadre established its political infrastructure and organized new guerrilla elements at the hamlet and village levels. As the link between guerrilla and main force units, local forces served as a reaction force for the former and as a pool of replacements and reinforcements for the latter. Having limited offensive capability, local forces usually attacked poorly defended, isolated outposts or weaker paramilitary forces, often at night and by ambush. Main force units were organized as battalions, regiments, and-as the insurgency matured-divisions. Subordinate to provincial, regional, and higher commands, such units were the strongest, most mobile, and most offensive-minded of the Viet Cong forces; their mission often was to attack and defeat a specific South Vietnamese unit.

Missions were assigned and approved by a political officer who, in most cases, was superior to the unit's military commander. Party policy, military discipline, and unit cohesion were inculcated and reinforced by three-man party cells in every unit. Among the insurgents, war was always the servant of policy.

As the Viet Cong's control over the population increased, their military forces grew in number and size. Squads and platoons became companies, companies formed battalions, and battalions were organized into regiments This process of creating and enlarging units continued as long as the Viet Cong had a base of support among the population. After 1959, however, infiltrators from the North also became important. Hanoi activated a special military transportation unit to control overland infiltration along the Ho Chi Minh Trail through Laos and Cambodia. Then a special naval unit was set up to conduct sea infiltration. At first, the infiltrators were southern-born Viet Minh soldiers who had regrouped north after the French Indochina War. Each year until 1964, thousands returned south to join or to form Viet Cong units, usually in the areas where they had originated. Such men served as experienced military or political cadres, as technicians, or as rank-and-file combatants wherever local recruitment was difficult.

When the pool of about 80,000 so-called regroupees ran dry, Hanoi began sending native North Vietnamese soldiers as individual replacements and reinforcements. In 1964 the Communists started to introduce entire North Vietnamese Army (NVA) units into the South. Among the infiltrators were senior cadres, who manned the expanding Viet Cong command system-regional headquarters, interprovincial commands, and the Central Office for South Vietnam (COSVN), the supreme military and political headquarters. As the southern branch of the Vietnamese Communist party COSVN was directly subordinate to the Central Committee in Hanoi; It's senior commanders were high-ranking officers of North Vietnam's Army. To equip the growing number of Viet Cong forces in the South, the insurgents continued to rely heavily on arms and supplies captured from South Vietnamese forces. But increasingly, large numbers of weapons, ammunition and other equipment arrived from the North, nearly all supplied by the Sino-Soviet bloc.

From a strength of approximately 5,000 at the start of 1959 the Viet Cong's ranks grew to about 100,000 at the end of 1964. The number of infiltrators alone during that period was estimated at 41,000. The growth of the insurgency reflected not only North Vietnam's skill in infiltrating men and weapons but South Vietnam's inability to control its porous borders, Diem's failure to develop a credible pacification program to reduce Viet Cong influence in the countryside, and the South Vietnamese Army's difficulties in reducing long-standing Viet Cong bases and secret zones. Such areas not only facilitated infiltration but were staging areas for operations; they contained training camps, hospitals, depots, workshops, and command centers. Many bases were in remote areas seldom visited by the army, such as the U Minh Forest or the Plain of Reeds. But others existed in the heart of populated areas, in the "liberated zones." There Viet Cong forces, dispersed among hamlets and villages, drew support from the local economy. From such centers the Viet Cong expanded their influence into adjacent areas that were nominally under Saigon's control.

A New President Takes Charge

Soon after John F. Kennedy became President in 1961, he sharply increased military and economic aid to South Vietnam to help Diem defeat the growing insurgency. For Kennedy, insurgencies (or "wars of national liberation" in the parlance of Communist leaders) were a challenge to international security every bit as serious as nuclear war. The administration's approach to both extremes of conflict rested on the precepts of the flexible response. Regarded as a form of "sub-limited" or small war, insurgency was treated largely as a military problem- conventional war writ small-and hence susceptible to resolution by timely and appropriate military action. Kennedy's success in applying calculated military pressures to compel the Soviet Union to remove its offensive missiles from Cuba in 1962 reinforced the administration's disposition to deal with other international crises, including the conflict in Vietnam, in a similar manner.

Though an advance over the New Look, his policy also had limitations. Long-term strategic planning tended to be sacrificed to short-term crisis management. Planners were all too apt to assume that all belligerents were rational and that the foe subscribed as they did to the seductive logic of the flexible response. Hoping to give the South Vietnamese a margin for success, Kennedy periodically authorized additional military aid and support between 1961 and November 1963, when he was assassinated. But potential benefits were nullified by the absence of a clear doctrine and a coherent operational strategy for the conduct of counterinsurgency, and by chronic military and political shortcomings on the part of the South Vietnamese.
 
The U.S. Army played a major role in Kennedy's "beef up" of the American advisory and support efforts in South Vietnam. In turn, that role was made possible in large measure by Kennedy's determination to increase the strength and capabilities of Army forces for both conventional and unconventional operations. Between 1961 and 1964 the Army's strength rose from about 850,000 to nearly a million men, and the number of combat divisions grew from eleven to sixteen. These increases were backed up by an ambitious program to modernize  Army equipment and, by stockpiling supplies and equipment at forward bases, to increase the deployability and readiness of Army combat forces. The build-up, however, did not prevent the call-up of 120,000 Reservists to active duty in the summer of 1961, a few months after Kennedy assumed office. Facing renewed Soviet threats to force the Western Powers out of Berlin, Kennedy mobilized the Army to reinforce NATO, if need be. But the mobilization revealed serious shortcomings in Reserve readiness and produced a swell of criticism and complaints from Congress and Reservists alike. Although Kennedy sought to remedy the deficiencies that were exposed and set in motion plans to reorganize the Reserves, the unhappy experience of the Berlin Crisis was fresh in the minds of national leaders when they faced the prospect of war in Vietnam a few years later.

Facing trouble spots in Latin America, Africa, and Southeast Asia, Kennedy took a keen interest in the U.S. Army's Special Forces, believing that their skills in unconventional warfare were well suited to countering insurgency. During his first year in office, he increased the strength of the Special Forces from about 1,500 to 9,000 and authorized them to wear a distinctive green beret. In the same year he greatly enlarged their role in South Vietnam. First under the auspices of the Central Intelligence Agency and then under a military commander, the Special Forces organized the highland tribes into the Civilian Irregular Defense Group (CIDG) and in time sought to recruit other ethnic groups and sects in the South as well. To this scheme, underwritten almost entirely by the United States, Diem gave only tepid support. Indeed, the civilian irregulars drew strength from groups traditionally hostile to Saigon. Treated with disdain by the lowland Vietnamese, the Montagnards developed close, trusting relations with their Army advisers. Special Forces detachment commanders frequently were the real leaders of CIDG units. This strong mutual bond of loyalty between adviser and highlander benefited operations, but some tribal leaders sought to exploit the special relationship to advance Montagnard political autonomy. On occasion, Special Forces advisers found themselves in the awkward position of mediating between militant Montagnards and South Vietnamese officials who were suspicious and wary of the Americans' sympathy for the highlanders.

Through a village self-defense and development program, the Special Forces aimed initially to create a military and political buffer to the growing Viet Cong influence in the Central Highlands. Within a few years, approximately 60,000 highlanders had enlisted in the CIDG program. As their participation increased, so too did the range of Special Forces activities. In addition to village defense programs, the Green Berets sponsored offensive guerrilla activities and border surveillance and control measures. To detect and impede the Viet Cong, camps were established astride infiltration corridors and near enemy base areas, especially along the Cambodian and Laotian borders. But the camps themselves were vulnerable to enemy attack and, despite their presence, infiltration continued. At times, border control diverted tribal units from village defense, the original heart of the CIDG program.

By 1965, as the military situation in the highlands worsened, many CIDG units had changed their character and begun to engage in quasi-conventional military operations. In some instances, irregulars under the leadership of Army Special Forces stood up to crack enemy regiments, offering much of the military resistance to enemy efforts to dominate the highlands. Yet the Special Forces-despite their efforts in South Vietnam and in Laos, where their teams helped to train and advise anti-Communist Laotian forces in the early 1960's-did not provide an antidote to the virulent insurgency in Vietnam. Long-standing animosities between Montagnard and Vietnamese prevented close, continuing co-operation between the South Vietnamese Army and the irregulars. Long on promises but short on action to improve the lot of the Montagnards, successive South Vietnamese regimes failed to win the loyalty of the tribesmen. And the Special Forces usually operated in areas that were remote from the main Viet Cong threat to the heavily populated and economically important Delta and coastal regions of the country.

Besides the Special Forces, the Army's most important contribution to the fight was the helicopter. Neither Kennedy nor the Army anticipated the rapid growth of aviation in South Vietnam when the first helicopter transportation company arrived in December 1961. Within three years, however, each of South Vietnam's divisions and corps was supported by Army helicopters, with the faster, more reliable and versatile UH-1 (Huey) replacing the older CH-21. In addition to transporting men and supplies, helicopters were used to reconnoiter, to evacuate wounded, and to provide command and control. The Vietnam conflict became the crucible in which Army airmobile and air assault tactics evolved. As armament was added-first machine gun-wielding door-gunners, and later rockets and mini-guns-armed helicopters began to protect troop carriers against antiaircraft fire, to suppress enemy fire around landing zones during air assaults, and to deliver fire support to troops on the ground. Army fixed-wing aircraft also flourished. Equipped with a variety of detection devices, the OV-1 Mohawk conducted day and night surveillance of Viet Cong bases and trails. The Caribou, with its sturdy frame and ability to land and take off on short, unimproved airfields, proved ideal to supply remote camps.

Army aviation revived old disagreements with the Air Force over the roles and missions of the two services and the adequacy of Air Force close air support. The expansion of the Army's own "air force" nevertheless continued, abetted by the Kennedy administration's interest in extending airmobility to all types of land warfare, from counterinsurgency to the nuclear battlefield. Secretary of Defense Robert S. McNamara himself encouraged the Army to test an experimental air assault division. During 1963 and 1964 the Army demonstrated that helicopters could successfully replace ground vehicles for mobility and provide fire support in lieu of ground artillery. The result was the creation in 1965 of the 1st Cavalry Division (Airmobile)-the first such unit in the Army. In South Vietnam the helicopter's effect on organization and operations was as sweeping as the influence of mechanized forces in World War II. Many of the operational concepts of airmobility, rooted in cavalry doctrine and operations, were pioneered by helicopter units between 1961 and 1964, and later adopted by the new airmobile division and by all Army combat units that fought in South Vietnam.

In addition to Army Special Forces and helicopters, Kennedy greatly expanded the entire American advisory effort. Advisers were placed at the sector (provincial) level and were permanently assigned to infantry battalions and certain lower echelon combat units; additional intelligence advisers were sent to South Vietnam. Wide use was made of temporary training teams in psychological warfare, civic action, engineering, and a variety of logistical functions. With the expansion of the advisory and support efforts came demands for better communications, intelligence, and medical, logistical, and administrative support, all of which the Army provided from its active forces, drawing upon skilled men and units from U.S.- based forces. The result was a slow, steady erosion of its capacity to meet worldwide contingency obligations. But if Vietnam depleted the Army, it also provided certain advantages. The war was a laboratory in which to test and evaluate new equipment and techniques applicable to counterinsurgency-among others, the use of chemical defoliants and herbicides, both to remove the jungle canopy that gave cover to the guerrillas and to destroy his crops. As the activities of all the services expanded, U.S. military strength in South Vietnam increased from under 700 at the start of 1960 to almost 24,000 by the end of 1964. Of these, 15,000 were Army and a little over 2,000 were Army advisers.

Changes in American command arrangements attested to the growing commitment. In February 1962 the Joint Chiefs of Staff established the United States Military Assistance Command, Vietnam (USMACV), in Saigon as the senior American military headquarters in South Vietnam, and appointed General Paul D. Harkins as commander (COMUSMACV). Harkins reported to the Commander in Chief, Pacific (CINCPAC), in Hawaii, but because of high-level interest in South Vietnam, enjoyed special access to military and civilian leaders in Washington as well. Soon MACV moved into the advisory effort hitherto directed by the Military Assistance Advisory Group. To simplify the advisory chain of command, the latter was disestablished in May 1964, and MACV took direct control. As the senior Army commander in South Vietnam, the MACV commander also commanded Army support units; for day-to-day operations, however, control of such units was vested in the corps and division senior advisers. For administrative and logistical support Army units looked to the U.S. Army Support Group, Vietnam (later the U.S. Army Support Command), which was established in mid-1962.

Though command arrangements worked tolerably well, complaints were heard in and out of the Army. Some officials pressed for a separate Army component commander, who would be responsible both for operations and for logistical support-an arrangement enjoyed by other services in South Vietnam. Airmen tended to believe that an Army command already existed, disguised as MACV. They believed that General Harkins, though a joint commander, favored the Army in the bitter interservice rivalry over the roles and missions of aviation in South Vietnam. Some critics thought his span of control excessive, for Harkins' responsibility extended to Thailand, where Army combat units had deployed in 1962, aiming to overawe Communist forces in neighboring Laos. The Army undertook several logistical projects in Thailand, and Army engineers, signalmen, and other support forces remained there after combat forces withdrew in the fall of 1962.

While the Americans strengthened their position in South Vietnam and Thailand, the Communists tightened their grip in Laos. In 1962 agreements on that small, land-locked nation were signed in Geneva requiring all foreign military forces to leave Laos. American advisers, including hundreds of Special Forces, departed. But the agreements were not honored by North Vietnam. Its army, together with Laotian Communist forces,  consolidated their hold on areas adjacent to both North and South Vietnam through which passed the network of jungle roads called the Ho Chi Minh Trail. As a result, it became easier to move supplies south to support the Viet Cong in the face of the new dangers embodied in U.S. advisers, weapons, and tactics.

Counterinsurgency Falters

At first the enhanced mobility and firepower afforded the South Vietnamese Army by helicopters, armored personnel carriers, and close air support surprised and overwhelmed the Viet Cong. Saigon's forces reacted more , quickly to insurgent attacks and penetrated many Viet Cong areas. Even more threatening to the insurgents was Diem's strategic hamlet program, launched in late 1961. Diem and his brother Ngo Dinh Nhu, an ardent sponsor of the program, hoped to create thousands of new, fortified villages, often by moving peasants from their existing homes. Hamlet construction and defense were the responsibility of the new residents, with paramilitary and ARVN forces providing initial security while the peasants were recruited and organized. As security improved, Diem and Nhu hoped to enact social, economic, and political reforms which, when fully carried out, would constitute Saigon's revolutionary response to Viet Cong promises of social and economic betterment. If successful, the program might destroy the insurgency by separating and protecting the rural population from the Viet Cong, threatening the rebellion's base of support.

By early 1963, however, the Viet Cong had learned to cope with the army's new weapons and more aggressive tactics and had begun a campaign to eliminate the strategic hamlets. The insurgents became adept at countering helicopters and slow-flying aircraft and learned the vulnerabilities of armored personnel carriers. In addition, their excellent intelligence, combined with the predictability of ARVN's tactics and pattern of operations, enabled the Viet Cong to evade or ambush government forces. The new weapons the United States had provided the South Vietnamese did not compensate for the stifling influence of poor leadership, dubious tactics, and inexperience. The much publicized defeat of government forces at the Delta village of Ap Bac in January 1963 demonstrated both the Viet Cong's skill in countering ARVN's new capabilities and the  latter's inherent weaknesses. Faulty intelligence, poorly planned and executed fire support, and over-cautious leadership contributed to the outcome. But Ap Bac's significance transcended a single battle. The defeat was a portent of things to come. Now able to challenge ARVN units of equal strength in quasi- conventional battles, the Viet Cong were moving into a more intense stage of revolutionary war.

As the Viet Cong became stronger and bolder, the South Vietnamese Army became more cautious and less offensive-minded. Government forces became reluctant to respond to Viet Cong depredations in the countryside, avoided night operations, and resorted to ponderous sweeps against vague military objectives, rarely making contact with their enemies. Meanwhile, the Viet Cong concentrated on destroying strategic hamlets, showing that they considered the settlements, rather than ARVN forces, the greater danger to the insurgency. Poorly defended hamlets and outposts were overrun or subverted by enemy agents who infiltrated with peasants arriving from the countryside.

The Viet Cong's campaign was aided by Saigon's failures. The government built too many hamlets to defend. Hamlet militia varied from those who were poorly trained and armed to those who were not trained or armed at all. Fearing that weapons given to the militia would fall to the Viet Cong, local officials often withheld arms. Forced relocation, use of forced peasant labor to construct hamlets, and tardy payment of compensation or relocation were but a few reasons why peasants turned against the program. Few meaningful reforms took place. Accurate information on the program's true condition and on the decline in rural security was hidden from Diem by officials eager to please him with reports of progress. False statistics and reports misled U.S. officials, too, about the progress of the counterinsurgency effort.

If the decline in rural security was not always apparent to Americans, the lack of enlightened political leadership on the part of Diem was all too obvious. Diem habitually interfered in military matters-bypassing the chain of command to order operations, forbidding commanders to take casualties, and appointing military leaders on the basis of political loyalty rather than competence. Many military and civilian appointees, especially province and district chiefs, were dishonest and put career and fortune above the national interest. When Buddhist opposition to certain policies erupted into violent antigovernment demonstrations in 1963, Diem's uncompromising stance and use of military force to suppress the demonstrators caused some generals to decide that the President was a liability in the fight against the Viet Cong. On 1 November, with American encouragement, a group of reform-minded generals ousted Diem, who was murdered along with his brother.

Political turmoil followed the coup. Emboldened, the insurgents stepped up operations and increased their control over many rural areas. North Vietnam's leaders decided to intensify the armed struggle, aiming to demoralize the South Vietnamese Army and further undermine political authority in the South. As Viet Cong military activity quickened, regular North Vietnamese Army units began to train for possible intervention in the war. Men and equipment continued to flow down the Ho Chi Minh Trail, with North Vietnamese conscripts replacing the dwindling pool of southerners who had belonged to the Viet Minh.

Setting the Stage for Confrontation

The critical state of rural security that came to light after Diem's death again prompted the United States to expand its military aid to Saigon. General Harkins and his successor General William C. Westmoreland urgently strove to revitalize pacification and counterinsurgency. Army advisers helped their Vietnamese counterparts to revise national and provincial pacification plans. They retained the concept of fortified hamlets as the heart of a new national counterinsurgency program, but corrected the old abuses, at least in theory. To help implement the program, Army advisers were assigned to the subsector (district) level for the first time, becoming more intimately involved in local pacification efforts and in paramilitary operations. Additional advisers were assigned to units and training centers, especially those of the Regional and Popular Forces (formerly called the Civil Guard and Self-Defense Corps). All Army activities, from aviation support to Special Forces, were strengthened in a concerted effort to undo the effects of years of Diem's mismanagement.

At the same time, American officials in Washington, Hawaii, and Saigon began to explore ways to increase military pressure against North Vietnam, In 1964 the South Vietnamese launched covert raids under MACV's auspices. Some military leaders, however, believed that only direct air strikes against North Vietnam would induce a change in Hanoi's policies by demonstrating American determination to defend South Vietnam's independence. Air strike plans ranged from immediate massive bombardment of military and industrial targets to gradually intensifying attacks spanning several months.

The interest in using air power reflected lingering sentiment in the United States against involving American ground forces once again in a land war on the Asian continent. Many of President Lyndon B. Johnson's advisers-among them General Maxwell D Taylor, who was appointed Ambassador to Saigon in mid-1964- believed that a carefully calibrated air campaign would be the most effective means of exerting pressure against the North  and, at the same time, the method least likely to provoke intervention by China. Taylor thought conventional Army ground forces ill suited to engage in day-to-day counterinsurgency operations against the Viet Cong in hamlets and villages. Ground forces might, however, be used to protect vital air bases in the South and to repel any North Vietnamese attack across the demilitarized zone, which separated North from South Vietnam. Together, a more vigorous counterinsurgency effort in the South and military pressure against the North might buy time for Saigon to put its political house in order, boost flagging military and civilian morale, and strengthen its military position in the event of a negotiated peace. Taylor and Westmoreland, the senior U.S. officials in South Vietnam, agreed that Hanoi was unlikely to change its course unless convinced that it could not succeed in the South. Both recognized that air strikes were neither a panacea nor a substitute for military efforts in the South.

As each side undertook more provocative military actions, the likelihood of a direct military confrontation between North Vietnam and the United States increased. The crisis came in early August 1964 in the international waters of the Gulf of Tonkin. North Vietnamese patrol boats attacked U.S. naval vessels engaged in surveillance of North Vietnam's coastal defenses. The Americans promptly launched retaliatory air strikes. At the request of President Johnson, Congress overwhelmingly passed the Southeast Asia Resolution-the so- called Gulf of Tonkin Resolution-authorizing all actions necessary to protect American forces and to provide  for the defense of the nation's allies in Southeast Asia. Considered by some in the administration as the equivalent of a declaration of war, this broad grant of authority encouraged Johnson to expand American military efforts within South Vietnam, against North Vietnam, and in Southeast Asia at large.

By late 1964, both sides were poised to increase their stake in the war. Regular NVA units had begun moving south and stood at the Laotian frontier, on the threshold of crossing into South Vietnam's Central Highlands. U.S. air and naval forces stood ready to renew their attacks. On 7 February 1965, Communist forces attacked an American compound in Pleiku in the Central Highlands and a few days later bombed American quarters in Qui Nhon. The United States promptly bombed military targets in the North. A few weeks later, President Johnson approved ROLLING THUNDER, a campaign of sustained, direct air strikes of progressively increasing strength against military and industrial targets in North Vietnam. Signs of intensifying conflict appeared in South Vietnam as well. Strengthening their forces at all echelons, from village guerrillas to main force regiments, the Viet Cong quickened military activity in late 1964 and in the first half of 1965. At Binh Gia, a village forty miles east of Saigon in Phuoc Tuy Province, a multiregimental Viet Cong force-possibly the 1st Viet Cong Infantry Division- fought and defeated several South Vietnamese battalions.

Throughout the spring the Viet Cong sought to disrupt pacification and oust the government from many rural  areas. The insurgents made deep inroads in the central coastal provinces and withstood government efforts to reduce their influence in the Delta and in the critical provinces around Saigon. Committed to static defense of key towns and bases, government forces were unable or unwilling to respond to attacks against rural communities. In late spring and early summer, strong Communist forces sought a major military victory over the South Vietnamese Army by attacking border posts and highland camps. The enemy also hoped to draw government forces from populated areas, to weaken pacification further. By whipsawing war-weary ARVN forces between coast and highland and by inflicting a series of damaging defeats against regular units, the enemy hoped to undermine military morale and popular confidence in the Saigon government. And by accelerating the dissolution of government military forces, already racked by high desertions and casualties, the Communists hoped to compel the South Vietnamese to abandon the battlefield and seek an all-Vietnamese political settlement that would compel the United States to leave South Vietnam.

By the summer of 1965, the Viet Cong, strengthened by several recently infiltrated NVA regiments, had gained the upper hand over government forces in some areas of South Vietnam. With U.S. close air support and the aid of Army helicopter gunships, Saigon's forces repelled many enemy attacks, but suffered heavy casualties. Elsewhere highland camps and border outposts had to be abandoned. ARVN's cumulative losses from battle deaths and desertions amounted to nearly a battalion a week. Saigon was hard pressed to find men to replenish these heavy losses and completely unable to match the growth of Communist forces from local recruitment and infiltration. Some American officials doubted whether the South Vietnamese could hold out until ROLLING THUNDER created pressures sufficiently strong to convince North Vietnam's leaders to reduce the level of combat in the South. General Westmoreland and others believed that U.S. ground forces were needed to stave off an irrevocable shift of the military and political balance in favor of the enemy.

For a variety of diplomatic, political, and military reasons, President Johnson approached with great caution any commitment of large ground combat forces to South Vietnam. Yet preparations had been under way for some time. In early March 1965, a few days after ROLLING THUNDER began, American Marines went ashore in South Vietnam to protect the large airfield at Da Nang-a defensive security mission. Even as they landed, General Harold K. Johnson, Chief of Staff of the Army, was in South Vietnam to assess the situation. Upon returning to Washington, he recommended a substantial increase in American military assistance, including several combat divisions. He wanted U.S. forces either to interdict the Laotian panhandle to stop infiltration or to counter a growing enemy threat in the central and northern provinces.

But President Johnson sanctioned only the dispatch of additional marines to increase security at Da Nang and to secure other coastal enclaves. He also authorized the Army to begin deploying nearly 20,000 logistical troops, the main body of the 1st Logistical Command, to Southeast Asia. (Westmoreland had requested such a command in late 1964.) At the same time the President modified the Marines' mission to allow them to conduct offensive operations close to their bases. A few weeks later, to protect American bases in the vicinity of Saigon, Johnson approved sending the first Army combat unit, the 173d Airborne Brigade (Separate), to South Vietnam. Arriving from Okinawa in early May, the brigade moved quickly to secure the air base at Bien Hoa, just northeast of Saigon. With its arrival, U.S. military strength in South Vietnam passed 50,000. Despite  added numbers and expanded missions, American ground forces had yet to engage the enemy in full-scale combat.

Indeed, the question of how best to use large numbers of American ground forces was still unresolved on the eve of their deployment. Focusing on population security and pacification, some planners saw U.S. combat forces concentrating their efforts in coastal enclaves and around key urban centers and bases. Under this plan, such forces would provide a security shield behind which the Vietnamese could expand the pacification zone; when required, American combat units would venture beyond their enclaves as mobile reaction forces.

This concept, largely defensive in nature, reflected the pattern established by the first Army combat units to enter South Vietnam. But the mobility and offensive firepower of U.S. ground units suggested their use in remote, sparsely populated regions to seek out and engage main force enemy units as they infiltrated into South Vietnam or emerged from their secret bases. While secure coastal logistical enclaves and base camps still would be required, the weight of the military effort would be focused on the destruction of enemy military units. Yet even in this alternative, American units would serve indirectly as a shield for pacification activities in the more heavily populated lowlands and Delta. A third proposal had particular  appeal to General Johnson. He wished to employ U.S. and allied ground forces across the Laotian panhandle to interdict enemy infiltration into South Vietnam. Here was a more direct and effective way to stop infiltration than the use of air power. Encumbered by military and political problems, the idea was revived periodically but always rejected. The pattern of deployment that actually developed in South Vietnam was a compromise between the first two concepts.

For any type of operations, secure logistical enclaves at deep- water ports (Cam Ranh Bay, Nha Trang, Qui Nhon, for example) were a military necessity. In such areas combat units arrived and bases developed for regional logistical complexes to support the troops. As the administration neared a decision on combat deployment, the Army began to identify and ready units for movement overseas and to prepare mobilization  plans for Selected Reserve forces. The dispatch of Army units to the Dominican Republic in May 1965 to forestall a leftist take-over caused only minor adjustments to the build-up plans. The episode nevertheless showed how unexpected demands elsewhere in the world could deplete the strategic reserve, and it underscored the importance of mobilization if the Army was to meet worldwide contingencies and supply trained combat  units to Westmoreland as well.

The prospect of deploying American ground forces also revived discussions of allied command arrangements. For a time, Westmoreland considered placing South Vietnamese and American forces under a single commander, an arrangement similar to that of U.S. and South Korean forces during the Korean War. In the face of South Vietnamese opposition, however, the idea was dropped. Arrangements with other allies were varied. Americans in South Vietnam were joined by combat units from Australia, New Zealand, South Korea, Thailand, and by noncombat elements from several other nations. Westmoreland entered into separate agreements with each commander in turn; the compacts ensured close co-operation with MACV, but fell short of giving Westmoreland command over the allied forces.

While diversity marked these arrangements, Westmoreland strove for unity within the American build-up. As forces began to deploy to South Vietnam, the Army again sought to elevate the U.S. Army, Vietnam (USARV), to a full-fledged Army component command with responsibility for combat operations. But Westmoreland successfully warded off the challenge to his dual role as unified commander of MACV and Army commander. For the remainder of the war, USARV performed solely in a logistical and administrative capacity; unlike MACV's air and naval component commands, the Army component did not exercise operational control over combat forces, special forces, or field advisers. However, through its logistical, engineer, signal, medical, military police, and aviation commands, all established in the course of the build-up, USARV commanded and managed a support base of unprecedented size and scope. Despite this victory, unity of command over the ground war in South Vietnam eluded Westmoreland, as did over-all control of U.S. military operations in support of the war. Most air and naval operations outside of South Vietnam, including ROLLING THUNDER, were carried out by the Commander in Chief, Pacific, and his air and naval commanders from his headquarters thousands of miles away in Hawaii. This patchwork of command arrangements contributed to the lack of a unified strategy, the fragmentation of operations, and the pursuit of parochial service interests to the detriment of the war effort. No single American commander had complete authority or responsibility to fashion an over-all strategy or to co-ordinate all military aspects of the war in Southeast Asia. Furthermore, Westmoreland labored under a variety of political and operational constraints on the use of the combat forces he did command. Like the Korean War, the struggle in South Vietnam was complicated by enemy sanctuaries and by geographical and political restrictions on allied operations. Ground forces were barred from operating across South Vietnam's borders into Cambodia, Laos, or North Vietnam, although the border areas of those countries were vital to the enemy's war effort. These factors narrowed Westmoreland's freedom of action and detracted from his efforts to make effective use of American military power.

Groundwork for Combat: Build-up and Strategy

On 28 July 1965, President Johnson announced plans to deploy additional combat units and to increase American military strength in South Vietnam to 175,000 by year's end. The Army already was preparing hundreds of units for duty in Southeast Asia, among them the newly activated 1st Cavalry Division (Airmobile). Other combat units-the 1st Brigade, 101st Airborne Division, and all three brigades of the 1st Infantry Division- were either ready to go or already on their way to Vietnam. Together with hundreds of support and logistical units, these combat units constituted the first phase of the build-up during the summer and fall of 1965.

At the same time, President Johnson decided not to mobilize any Reserve units. The President's decision profoundly affected the manner in which the Army supported and sustained the build-up. To meet the call for additional combat forces and to obtain manpower to enlarge its training base and to maintain a pool for rotation and replacement of soldiers in South Vietnam, the Army had to increase its active strength, over the next three years, by nearly 1.5 million men. Necessarily, it relied on larger draft calls and voluntary enlistments, supplementing them with heavy draw downs of experienced soldiers from units in Europe and South Korea and extensions of some tours of duty to retain specialists, technicians, and cadres who could train  recruits or round out deploying units. Combat units assigned to the strategic reserve were used to meet a large portion of MACV's force requirements, and Reservists were not available to replace them, Mobilization could have eased the additional burden of providing noncommissioned officers (NCO's) and officers to man the Army's growing training bases. As matters stood, requirements for experienced cadres competed with the demands for seasoned leaders in units deploying to South Vietnam.

The personnel turbulence caused by competing demands for the Army's limited manpower was intensified by a one-year tour of duty in South Vietnam. A large number of men was needed to sustain the rotational base, often necessitating the quick return to Vietnam of men with critical skills. The heightened demand for leaders led to accelerated training programs and the lowering of standards for NCO's and junior officers. Moreover, the one-year tour deprived units in South Vietnam of experienced leadership. In time, the infusion of less-seasoned NCO's and officers contributed to a host of morale problems that afflicted some Army units. At a deeper level, the administration's decision against calling the Reserves to active duty sent the wrong signal to friends and enemies alike, implying that the nation lacked the resolution to support an effort of the magnitude needed to achieve American objectives in South Vietnam.

Hence the Army began to organize additional combat units. Three light infantry brigades were activated, and the 9th Infantry Division was reactivated. In the meantime the 4th and 25th Infantry Divisions were alerted for deployment to South Vietnam. With the exception of a brigade of the 25th, all of the combat units activated and alerted during the second half of 1965 deployed to South Vietnam during 1966 and 1967. By the  end of 1965, U.S. military strength in South Vietnam had reached 184,000; a year later it stood at 385,000; and by the end of 1967 it approached 490,000. Army personnel accounted for nearly two-thirds of the total. Of the Army's eighteen divisions, at the end of 1967, seven were serving in South Vietnam.

Facing a deteriorating military situation, Westmoreland in the summer of 1965 planned to use his combat units to blunt the enemy's spring-summer offensive. As they arrived in the country, Westmoreland moved them into a defensive arc around Saigon and secured bases for the arrival of subsequent units. His initial aim was defensive-to stop losing the war and to build a structure that could support a later transition to an  offensive campaign. As additional troops poured in, Westmoreland planned to seek out and defeat major enemy forces. Throughout both phases, the South Vietnamese, relieved of major combat tasks, were to refurbish their forces and conduct an aggressive pacification program behind the American shield. In a third and final stage, as enemy main force units were driven into their secret zones and bases, Westmoreland hoped to achieve  victory by destroying those sanctuaries and shifting the weight of the military effort to pacification, thereby at last subduing the Viet Cong throughout rural South Vietnam.

The fulfillment of this concept rested not only on the success of American efforts to find and defeat enemy forces, but on the success of Saigon's pacification program. In June 1965 the last in a series of coups that followed Diem's overthrow brought in a military junta headed by Lt Gen Nguyen Van Thieu as Chief of State and Air Vice Marshal Nguyen Cao Ky as Prime Minister. The new government provided the political stability requisite for successful pacification. Success hinged also on the ability of the U.S. air campaign against the North to reduce the infiltration of men and material dampening the intensity of combat in the South and inducing Communist leaders in Hanoi to alter their long-term strategic goals. Should any strand of this threefold strategy-the campaign against Communist forces in the South, Saigon's pacification program, and the air war in the North-falter Westmoreland's prospects would become poorer. Yet he was directly responsible for only one element, the U.S. military effort in the South. To a lesser degree, through American advice and assistance to the South Vietnamese forces, he also influenced Saigon's efforts to suppress the Viet Cong and to carry out pacification.

Army Operations in III and IV Corps, 1965-1967

Centered on the defense of Saigon, Westmoreland's concept of operations in the III Corps area had a clarity of design and purpose that was not always apparent elsewhere in South Vietnam.  Nearly two years would pass before U.S. forces could maintain a security belt around the capital and at the same time attack the enemy's bases. But Westmoreland's ultimate aims and the difficulties he would encounter were both foreshadowed by the initial combat operations in the summer and fall of 1965.

Joined by newly arrived Australian infantrymen, the 173d Airborne Brigade during June began operations in War Zone D, a longtime enemy base north of Saigon. Though diverted several times to other tasks, the brigade gained experience in conducting heliborne assaults and accustomed itself to the rigors of jungle operations. It also established a pattern of operations that was to grow all too familiar. Airmobile assaults, often in the wake of B-52 air strikes, were followed by extensive patrolling, episodic contact with the Viet Cong, and withdrawal after a few days' stay in the enemy's territory. In early November the airborne soldiers uncovered evidence of the enemy's recent and hasty departure-abandoned camps, recently vacated tunnels and caches of food and supplies. However, the Viet Cong by observing the brigade began to formulate plans for dealing with the Americans.

On 8 November, moving deeper into War Zone D, the brigade encountered the first significant resistance. A multibattallion Viet Cong force attacked at close quarters and forced the Americans into a tight defensive perimeter. Hand-to-hand combat ensued as the enemy tried to "hug" American soldiers to prevent the delivery of supporting air and artillery fire. Unable to prepare a landing zone to receive reinforcements or to evacuate casualties, the beleaguered Americans withstood repeated enemy assaults. At nightfall the Viet Cong ceased their attack and withdrew under cover of darkness. Next morning, when reinforcements arrived, the brigade pursued the enemy, finding evidence that he had suffered heavy casualties. Such operations inflicted losses but failed either to destroy the enemy's base or to prevent him from returning to it later on.

Like the airborne brigade, the 1st Infantry Division initially divided its efforts. In addition to securing its base camps north of Saigon, the division helped South Vietnamese forces clear an area west of the capital in the vicinity of Cu Chi in Hau Nghia Province. Reacting to reports of enemy troop concentrations, units of the division launched a series of operations in the fall of 1965 and early 1966 that entailed quick forays into the Ho Bo and Boi Loi woods, the Michelin Rubber Plantation, the Rung Sat swamp, and War Zones C and D.  In Operation MASTIFF, for example, the division sought to disrupt Viet Cong infiltration routes between War Zones C and D that crossed the Boi Loi woods in Tay Ninh Province, an area that had not been penetrated by government forces for several years.

But defense of Saigon was the first duty of the "Big Red One" as well as of the 25th Infantry Division, which arrived in the spring of 1966. The 1st Division took up a position protecting the northern approaches, blocking Route 13 from the Cambodian border. The 25th guarded the western approaches, chiefly Route 1 and the Saigon River. The two brigades of the 25th Division served also as a buffer between Saigon and the enemy's base areas in Tay Ninh Province. Westmoreland hoped, however, that the 25th Division would loosen the insurgents' tenacious hold on Hau Nghia Province as well. Here American soldiers found to their amazement that the division's camp at Cu Chi had been constructed atop an extensive Viet Cong tunnel complex. Extending over an area of several miles, this subterranean network, one of several in the region, contained hospitals, command centers, and storage sites. The complex, though partially destroyed by Army "tunnel rats," was never completely eliminated and lasted for the duration of the war. The 25th Division worked closely with South Vietnamese Army and paramilitary forces throughout 1966 and 1967 to foster pacification in Hau Nghia and to secure its own base. But suppressing insurgency in Hau Nghia proved as difficult as eradicating the tunnels at Cu Chi.

As the number of Army combat units in Vietnam grew larger, Westmoreland established two corps-size commands, I Field Force in the II Corps area and II Field Force in the III Corps area. Reporting directly to the MACV commander, the field force commander was the senior Army tactical commander in his area and the senior U.S. adviser to ARVN forces there. Working closely with his South Vietnamese counterpart, he coordinated ARVN and American operations by establishing territorial priorities for combat and pacification efforts. Through his deputy senior adviser, a position established in 1967, the field force commander was able to keep abreast both of the activities of U.S. sector (province) and subsector (district) advisers and of the progress of Saigon's pacification efforts. A similar arrangement was set up in I Corps, where the commander of the III Marine Amphibious Force was the equivalent of a field force commander. Only in IV Corps, in the Mekong Delta where few American combat units served, did Westmoreland choose not to establish a corps-size command. There the senior U.S. adviser served as COMUSMACV's representative; he commanded Army advisory and support units, but no combat units.

Although Army commanders in III Corps were eager to seek out and engage enemy main force units in their strongholds along the Cambodian border, operations at first were devoted to base and area security and to clearing and rehabilitating roads. The 1st Infantry Division's first major encounter with the Viet Cong occurred in November as division elements carried out a routine road security operation along Route 13, in  the vicinity of the village of Bau Bang. Trapping convoys along Route 13 had long been a profitable Viet Cong tactic. Ambushed by a large, well- entrenched enemy force, division troops reacted aggressively and mounted a successful counterattack. But the road was by no means secured; close to enemy bases, the Cambodian border, and Saigon, Route 13 would be the site of several major battles in years to come.

Roads were a major concern of U.S. commanders. In some operations, infantrymen provided security as Army engineers improved neglected routes. Defoliants and the Rome plow-a bulldozer modified with sharp front blades-removed from the sides of important highways the jungle growth that provided cover for Viet Cong ambushes. Road-clearing operations also contributed to pacification by providing peasants with secure access to local markets. In III Corps, with its important road network radiating from Saigon, ground mobility was as essential as airmobility for the conduct of military operations. Lacking as many helicopters as the airmobile division, the 1st and 25th Infantry Divisions, like all Army units in South Vietnam, strained the resources of their own aviation support units and of other Army aviation units providing area support to obtain the maximum airmobile capacity for each operation. Nevertheless, on many occasions the Army found itself road bound.

Road and convoy security was also the original justification for introducing Army mechanized and armor units into South Vietnam in 1966. At first Westmoreland was reluctant to bring heavy mechanized equipment into South Vietnam, for it seemed ill suited either to counterinsurgency operations or to operations during the monsoon season, when all but a few roads were impassable. Armor advocates pressed Westmoreland to reconsider his policy. Operation CIRCLE PINES, carried out by elements of the 25th Infantry Division in the spring of 1966, successfully combined an infantry force and an armor battalion. This experience, together with new studies indicating a greater potential for mechanized forces, led Westmoreland to reverse his original policy and request deployment of the 11th Armored Cavalry Regiment, with its full complement of tanks, to Vietnam.

Arriving in III Corps in the last half of 1966, the regiment set up base at Xuan Loc, on Route 1 northeast of Saigon in Long Khanh Province. In addition to assuming an area support mission and strengthening the eastern approaches to Saigon as part of Westmoreland's security belt around the capital, squadrons of the regiment supported Army units throughout the corps zone, often "homesteading" with other brigades or divisions.

Route security, however, was only the first step in carving out a larger role for Army mechanized forces. Facing an enemy who employed no armor, American mechanized units, often in conjunction with airmobile assaults, acted both as blocking or holding forces and as assault or reaction forces, where terrain permitted. "Jungle bashing," as offensive armor operations were sometimes called, had its uses but also its  limitations. The intimidating presence of tanks and personnel carriers was often nullified by their cumbersomeness and noise, which alerted the enemy to an impending attack. The Viet Cong also took countermeasures to immobilize tracked vehicles. Crude tank traps, locally manufactured mines (often made of plastic to thwart discovery by metal detectors), and well-aimed rocket or recoilless rifle rounds could disable a tank or personnel carrier. Together with the dust and tropical humidity, such weapons placed a heavy burden on Army maintenance units. Yet mechanized units brought the allies enhanced mobility and firepower and often were essential to counter ambushes or destroy an enemy force protected by bunkers.

As Army strength increased in III Corps, Westmoreland encouraged his units to operate farther afield. In early 1966 intelligence reports indicated that enemy strength and activity were increasing in many of his base areas. In two operations during the early spring of 1966, units of the 1st and 25th Divisions discovered Viet Cong training camps and supply dumps, some of the sites honeycombed with tunnels. But they failed to engage major enemy forces. As Army units made the deepest penetration of War Zone C since 1961, all signs pointed to the foe's hasty withdrawal into Cambodia. An airmobile raid failed to locate the enemy's command center, COSVN. (COSVN, in fact, was fragmented among several sites in Tay Ninh Province and in nearby Cambodia.) Like the 173d Airborne Brigade's operations, the new attacks had no lasting effects.

By May 1966 an ominous build-up of enemy forces, among them NVA regiments that had infiltrated south, was detected in Phuoc Long and Binh Long Provinces in northern III Corps. U.S. commanders viewed the build-up as a portent of the enemy's spring offensive, plans for which included an attack on the district town of Loc Ninh and on a nearby Special Forces camp. The 1st Division responded, sending a brigade to secure Route 13.  But the threat to Loc Ninh heightened in early June, when regiments of the 9th Viet Cong Division took up positions around the town. The arrival of American reinforcements apparently prevented an assault. About a week later, however, an enemy regiment was spotted in fortified positions in a rubber plantation adjacent to Loc Ninh. Battered by massive air and artillery strikes, the regiment was dislodged and its position overrun, ending the Route security, however, was only the first step in carving out a larger role for Army mechanized forces. Facing an enemy who employed no armor, American mechanized units, often in conjunction with airmobile assaults, acted both as blocking or holding forces and as assault or reaction forces, where terrain permitted. "Jungle bashing," as offensive armor operations were sometimes called, had its uses but also its limitations. The intimidating presence of tanks and personnel carriers was often nullified by their cumbersomeness and noise, which alerted the enemy to an impending attack. The Viet Cong also took countermeasures to immobilize tracked vehicles. Crude tank traps, locally manufactured mines (often made of plastic to thwart discovery by metal detectors), and well-aimed rocket or recoilless rifle rounds could disable a tank or personnel carrier. Together with the dust and tropical humidity, such weapons placed a heavy burden on Army maintenance units. Yet mechanized units brought the allies enhanced mobility and firepower and often were essential to counter ambushes or destroy an enemy force protected by bunkers.

As Army strength increased in III Corps, Westmoreland encouraged his units to operate farther afield. In early 1966 intelligence reports indicated that enemy strength and activity were increasing in many of his base areas. In two operations during the early spring of 1966, units of the 1st and 25th Divisions discovered Viet Cong training camps and supply dumps, some of the sites honeycombed with tunnels. But they failed to engage major enemy forces. As Army units made the deepest penetration of War Zone C since 1961, all signs pointed to the foe's hasty withdrawal into Cambodia. An airmobile raid failed to locate the enemy's command center, COSVN. (COSVN, in fact, was fragmented among several sites in Tay Ninh Province and in nearby Cambodia.) Like the 173d Airborne Brigade's operations, the new attacks had no lasting effects.

By May 1966 an ominous build-up of enemy forces, among them NVA regiments that had infiltrated south, was detected in Phuoc Long and Binh Long Provinces in northern III Corps. U.S. commanders viewed the build-up as a portent of the enemy's spring offensive, plans for which included an attack on the district town of Loc Ninh and on a nearby Special Forces camp. The 1st Division responded, sending a brigade to secure Route 13. But the threat to Loc Ninh heightened in early June, when regiments of the 9th Viet Cong Division took up positions around the town. The arrival of American reinforcements apparently prevented an assault. About a week later, however, an enemy regiment was spotted in fortified positions in a rubber plantation adjacent to Loc Ninh. Battered by massive air and artillery strikes, the regiment was dislodged and its position  verrun, ending the threat. Americans recorded other successes, trapping Viet Cong ambushers in a counterambush, securing Loc Ninh, and spoiling the enemy's spring offensive. But if the enemy still underestimated the mobility and firepower that U.S. commanders could bring to bear, he had learned how easily Americans could be lured away from their base camps.

By the summer of 1966 Westmoreland believed he had stopped the losing trend of a year earlier and could begin the second phase of his general campaign strategy. This entailed aggressive operations to search out and destroy enemy main force units, in addition to continued efforts to improve security in the populated areas of III Corps. In Operation ATTLEBORO he sent the 196th Infantry Brigade and the 3d Brigade, 4th Infantry Division, to Tay Ninh Province to bolster the security of the province seat. Westmoreland's challenge prompted COSVN to send the 9th Viet Cong Division on a "countersweep," the enemy's term for operations to counter allied search and destroy tactics. Moving deeper into the enemy's stronghold, the recently arrived and inexperienced 196th Infantry Brigade sparred with the enemy. Then an intense battle erupted, as elements of the brigade were isolated and surprised by a large enemy force. Operation ATTLEBORO quickly grew to a multidivision struggle as American commanders sought to maintain contact with the Viet Cong and to aid their own surrounded forces. Within a matter of days, elements of the 1st and 25th Divisions, the 173d Airborne Brigade, and the 11th Armored Cavalry Regiment had converged on War Zone C. Control of ATTLEBORO passed in turn from the 196th to the 1st Division and finally to the II Field Force, making it the first Army operation in South Vietnam to be controlled by a corps-size headquarters. With over 22,000 U.S. troops participating, the battle had become the largest of the war. Yet combat occurred most often at the platoon and company levels, usually at night. As the number of American troops increased, the 9th Viet Cong Division shied away, withdrawing across the Cambodian border. Then Army forces departed, leaving to the Special Forces the task of detecting the enemy's inevitable return.

As the threat along the border abated, Westmoreland turned his attention to the enemy's secret zones near Saigon, among them the so-called Iron Triangle in Binh Duong Province. Harboring the headquarters of Military Region IV, the Communist command that directed military and terrorist activity in and around the capital, this stronghold had gone undisturbed for several years. Westmoreland hoped to find the command center, disrupt Viet Cong activity in the capital region, and allow South Vietnamese forces to accelerate pacification and uproot the stubborn Viet Cong political organization that flourished in many villages and hamlets.

Operation CEDAR FALLS began on 8 January 1967 with the objectives of destroying the headquarters, interdicting the movement of enemy forces into the major war zones in III Corps, and defeating Viet Cong units encamped there. Like ATTLEBORO before it, CEDAR FALLS tapped the manpower and resources of nearly every major Army unit in the corps area. A series of preliminary maneuvers brought Army units into position. Several air assaults sealed off the Iron Triangle, exploiting the natural barriers of the rivers that formed two of its boundaries. Then American units began a series of sweeps to push the enemy toward the blocking forces. At the village of Ben Suc, long under the sway of the insurgents, sixty helicopters descended into seven landing zones in less than a minute. Ben Suc was surrounded, its entire population evacuated, and the village and its tunnel complex destroyed. But insurgent forces had fled before the heliborne assault. As CEDAR FALLS progressed, U.S. troops destroyed hundreds of enemy fortifications, captured large quantities of supplies and food, and evacuated other hamlets. Contact with the enemy was fleeting. Most of the Viet Cong, including the high-level cadre of the regional command, had escaped, sometimes infiltrating through allied lines.

By the time Army units left the Iron Triangle, MACV had already received reports that Viet Cong and NVA regiments were returning to War Zone C in preparation for a spring offensive. This time Westmoreland hoped to prevent Communist forces from escaping into Cambodia, as they had done in ATTLEBORO. From forward field positions established during earlier operations, elements of the 25th and 1st Divisions, the 196th Infantry Brigade, and the 9th Armored Cavalry Regiment launched JUNCTION CITY, moving rapidly to establish a cordon around the war zone and to begin a new sweep of the base area. As airmobile and mechanized units moved into positions on the morning of 21 February 1967, elements of the 173d Airborne Brigade made the only parachute drop of the Vietnam War-and the first combat airborne assault since the Korean War-to establish a blocking position near the Cambodian border. Then other U.S. units entered the horseshoe-shaped area of operations through its open end.

Despite the emphasis on speed and surprise, Army units did not encounter many enemy troops at the outset. As the operation entered its second phase, however, American forces concentrated their efforts in the eastern portion of War Zone C, close to Route 13. Here several violent battles erupted, as Communist forces tried to isolate and defeat individual units and possibly also to screen the retreat of their comrades into Cambodia. On 19 March a mechanized unit of the 9th Infantry Division was attacked and nearly overrun along Route 13 near the battered village of Bau Bang. The combined firepower of armored cavalry, supporting artillery, and close air support finally caused the enemy to break contact. A few days later, at Fire Support Base GOLD, in the vicinity of Soui Tre, an infantry and artillery battalion of the 25th Infantry engaged the 272d Viet Cong Regiment. Behind an intense, walking mortar barrage, enemy troops breached GOLD's defensive perimeter and rushed into the base. Man-to-man combat ensued. A complete disaster was averted when Army artillerymen lowered their howitzers and fired, directly into the oncoming enemy, Beehive artillery rounds that contained hundreds of dartlike projectiles. The last major encounter with enemy troops during JUNCTION CITY occurred at the end of March, when elements of two Viet Cong regiments, the 271st and the 70th (the latter directly subordinate to COSVN) attacked a battalion of the 1st Infantry Division in a night defensive position deep in War Zone C, near the Cambodian border. The lopsided casualties-over 600 enemy killed in contrast to 10 Americans-forcefully illustrated once again the U.S. ability to call in overwhelmingly superior fire support by artillery, armed helicopters, and tactical aircraft.

Thereafter, JUNCTION CITY became a pale shadow of the multidivision effort it had been at its outset. Most Army units were withdrawn, either to return to their bases or to participate in other operations. The 196th Infantry Brigade was transferred to I Corps to help replace Marine forces sent north to meet a growing enemy threat near the demilitarized zone. Contacts with enemy forces in this final phase were meager. Again a planned Viet Cong offensive had been aborted; the enemy himself escaped, though not unscathed.

In the wake of JUNCTION CITY, MACV's attention reverted to the still critical security conditions around Saigon. The 1st Infantry Division returned to War Zone D to search for the 271st Viet Cong Regiment and to disrupt the insurgents' lines of communications between War Zones C and D. Despite two major contacts, the main body of the regiment eluded its American pursuers. Army units again returned to the Iron Triangle between April and July 1967, after enemy forces were detected in their old stronghold. Supplies and documents were found in quantities even larger than those discovered in CEDAR FALLS. Once again, however, encounters with the Communists were fleeting. The enemy's reappearance in the Iron Triangle and War Zone D, combined with rocket and mortar attacks on U.S. bases around Saigon, heightened Westmoreland's concern about the  security of the capital. When the 1st Infantry Division's base at Phuoc Vinh and the Bien Hoa Air Base were attacked in mid-1967, the division mounted operations into the Ong Dong jungle and the Vinh Loi woods. Other operations swept the jungles and villages of Bien Hoa Province and sought once again to support pacification in Hau Nghia Province.

These actions pointed up a basic problem. The large, multidivision operations into the enemy's war zones produced some benefits for the pacification campaign; by keeping enemy main force regiments at bay, Westmoreland impeded their access to heavily populated areas and prevented them from reinforcing Viet Cong provincial and district forces. Yet when American units were shifted to the border, the local Viet Cong units gained a measure of relief. Westmoreland faced a strategic dilemma: he could not afford to keep substantial forces away from their bases for more than a few months at a time without jeopardizing local security. Unless he received additional forces, Westmoreland would always be torn between two operational imperatives. By the summer of 1967, MACV's likelihood of receiving more combat troops, beyond those scheduled to deploy during the latter half of the year and in early 1968, had become remote. In Washington the administration turned down his request for an additional 200,000 men.

Meanwhile, however, the 9th Infantry Division and the 199th Infantry Brigade arrived in South Vietnam. Westmoreland stationed the brigade at Bien Hoa, where it embarked on FAIRFAX, a year-long operation in which it worked closely with a South Vietnamese ranger group to improve security in Gia Dinh Province, which surrounded the capital. Units of the brigade "paired off" with South Vietnamese rangers and, working closely with paramilitary and police forces, sought to uproot the very active Viet Cong local forces and destroy the enemy's political infrastructure. Typical activities included ambushes by combined forces; cordon and search operations in villages and hamlets, often in conjunction with the Vietnamese police; psychological and civic action operations; surprise road blocks to search for contraband and Viet Cong supporters; and training programs to develop proficient military and local self-defense capabilities.

Likewise, the 9th Infantry Division set up bases east and south of Saigon. One brigade deployed to Bear Cat; another set up camp at Tan An in Long An Province, south of Saigon, where it sought to secure portions of Route 4, an important north-south highway connecting Saigon with the rice-rich lower Delta. Further south, the 2d Brigade, 9th Infantry Division, established its base at Dong Tam in Dinh Tuong Province in IV Corps. Located in the midst of rice paddies and swamps, Dong Tam was created by Army engineers with sand dredged from the My Tho River. From this 600-acre base, the brigade began a series of riverine operations unique to the Army's experience in South Vietnam.

To patrol and fight in the inundated marshlands and rice paddies and along the numerous canals and waterways crossing the Delta, the Army modernized the concept of riverine warfare employed during the Civil War by Union forces on the Mississippi River and by the French during the Indochina War. The Mobile Riverine Force utilized a joint Army-Navy task force controlled by a ground commander. In contrast to amphibious operations, where control reverts to the ground commander only after the force is ashore, riverine warfare was an extension of land combat with infantry units traveling by water rather than by trucks or tracked vehicles, Aided by a Navy river support squadron and river assault squadron, infantrymen were housed on barracks ships and supported by gunships or fire support boats called monitors. Howitzers and mortars mounted on barges provided artillery support. The 2d Brigade, 9th Infantry Division, began operations against the Cam Son Secret Zone, approximately 10 miles west of Dong Tam, in May 1967.

Meanwhile, the war of main force units along the borders waxed and waned in relation to seasonal weather cycles, which affected the enemy's pattern of logistical activity, his ability to infiltrate men and supplies from North Vietnam, and his penchant for meticulous preparation of the battlefield. By the fall of 1967, enemy activity had increased again in the base areas, and sizable forces began appearing along South Vietnam's border from the demilitarized zone to III Corps. By the year's end, American forces had returned to War Zone C to screen the Cambodian border to prevent Communist forces from re-entering South Vietnam. Units of the 25th Infantry Division that had been conducting operations in the vicinity of Saigon moved to the border. Elements of the 1st Infantry Division had resumed road-clearing operations along Route 13, but the division soon faced another major enemy effort to capture Loc Ninh. On 29 October Viet Cong units assaulted the CIDG camp and the district Command post, breaching the defense perimeter. Intense air and artillery fire prevented its complete loss. Within a few hours, South Vietnamese and U.S. reinforcements reached Loc Ninh, their arrival made possible by the enemy's failure to capture the local airstrip.

When the build-up ended, ten Army battalions were positioned within Loc Ninh and between the town and the Cambodian border. During the next two days allied units warded off repeated enemy attacks as Communist forces desperately tried to score a victory. Tactical air support and artillery fire prevented the enemy form massing though he outnumbered allied forces by about ten to one. At end of a ten-day battle, over 800 enemy were left on the battlefield, while allied deaths numbered only 50. Some 452 close air support sorties, 8 B-52 bomber strikes, and 30,125 rounds of artillery had been directed at the enemy. Once again, Loc Ninh had served as a lightning rod to attract U.S. forces to the border. The pattern of two wars-one in the villages,  one on the border-continued without decision.

Army Operations in II and I Corps, 1965-1967

Spearheaded by at least three NVA regiments, Communist forces mounted a strong offensive in South Vietnam's Central Highlands during the summer of 1965, overrunning border camps and besieging some district towns. Here the enemy threatened to cut the nation in two. To meet the danger, Westmoreland proposed to introduce the newly organized Army airmobile division, the 1st Cavalry Division, with its large contingent of helicopters, directly into the highlands. Some of his superiors in Hawaii and Washington opposed this plan, preferring to secure coastal bases. Though Westmoreland contended that enclave security made poor use of U.S. mobility and offensive firepower, he was unable to overcome the fear of an American Dien Bien Phu, if a unit in the highlands should be isolated and cut off from the sea.

In the end, the deployment of Army forces to II Corps reflected a compromise. As additional American and South Korean forces arrived during 1965 and 1966, they often reinforced South Vietnamese efforts to secure coastal enclaves, usually centered on the most important cities and ports. At Phan Thiet, Tuy Hoa, Qui Nhon, Nha Trang, and Cam Ranh Bay, allied forces provided area security, not only protecting the ports and logistical complexes that developed in many of these locations, but also assisting Saigon's forces to expand the pacified zone that extended from the urban cores to the countryside.

Here, as in III Corps, Westmoreland addressed two enemy threats. Local insurgents menaced populated areas along the coastal plain, while enemy main force units intermittently pushed forward in the western highlands. Between the two regions stretched the piedmont, a transitional area in whose lush valleys lived many South Vietnamese. In the piedmont's craggy hills and jungle-covered uplands, local and main force Viet Cong units had long flourished by exacting food and taxes from the lowland population through a well-entrenched shadow government. Although the enemy's bases in the piedmont did not have the notoriety of the secret zones near Saigon, they served similar purposes, harboring units, command centers, and training and logistical facilities. Extensions of the Ho Chi Minh Trail ran from the highlands through the piedmont to the coast, facilitating the movement of enemy units and supplies from province to province. To be effective, allied  operations on the coast had to uproot local units living amid the population and to eradicate the enemy base areas in the piedmont, together with the main force units that supported the village and hamlet guerrillas.

Despite their sparse population and limited economic resources, the highlands had a strategic importance equal to and perhaps greater than the coastal plain. Around the key highland towns- Pleiku, Kontum, Ban Me Thuot, and Da Lat-South Vietnamese and U.S. forces had created enclaves. Allied forces protected the few roads that traversed the highlands, screened the border, and reinforced outposts and Montagnard settlements from which the irregulars and Army Special Forces sought to detect enemy cross- border movements and to strengthen tribal resistance to the Communists. Such border posts and tribal camps, rather than major towns, most often were the object of enemy attacks. Combined with road interdiction, such attacks enabled the Communists to disperse the limited number of defenders and to discourage the maintenance of outposts.

Such actions served a larger strategic objective. The enemy planned to develop the highlands into a major base area from which to mount or support operations in other areas. A Communist-dominated highlands would be a strategic fulcrum, enabling the enemy to shift the weight of his operations to any part of South Vietnam. The highlands also formed a "killing zone" where Communist forces could mass. Challenging American forces had become the principal objective of leaders in Hanoi, who saw their plans to undermine Saigon's military resistance thwarted by U.S. intervention. Salient victories against Americans, they believed, might deter a further build-up and weaken Washington's resolve to continue the war.

The 1st Cavalry Division (Airmobile) moved with its 435 helicopters into this hornet's nest in September 1965, establishing its main base at An Khe, a government stronghold on Route 19, halfway between the coastal port of Qui Nhon and the highland city of Pleiku. The location was strategic: at An Khe the division could help to keep open the vital east-west road from the coast to the highlands and could pivot between the highlands and the coastal districts, where the Viet Cong had made deep inroads. Meanwhile, the 1st Brigade, 101st Airborne Division, had begun operations in the rugged Song Con valley, about 18 miles northeast of An Khe. Here, on 18 September, one battalion ran into heavy fire from an enemy force in the tree line around its landing zone. Four helicopters were lost and three company commanders killed; reinforcements could not land because of the intense enemy fire. With the fight at close quarters, the Americans were unable to call in close air support, armed gunships, and artillery fire, except at the risk of their own lives. But as the enemy pressed them back, supporting fires were placed almost on top of the contending forces. At dusk the fighting subsided; as the Americans steeled themselves for a night attack, the enemy, hard hit by almost 100 air strikes and 11,000 rounds of artillery, slipped away. Inspection of the battlefield revealed that the Americans had unwittingly landed in the midst of a heavily bunkered enemy base.

The fight had many hallmarks of highland battles that were to come. Americans had little information about enemy forces or the area of operations; the enemy could "hug" Army units to nullify their massive advantage in firepower. In compensation, the enemy underestimated the accuracy of such fire and the willingness of U.S. commanders to call it in even when fighting at close quarters. Finally, enemy forces when pressed too hard  could usually escape, and pursuit, as a rule, was futile.

Less than a month later the newly arrived airmobile division received its own baptism of combat. The North Vietnamese Army attacked a Special Forces camp at Plei Me; when it was repulsed, Westmoreland directed the division to launch an offensive to locate and destroy enemy regiments that had been identified in the vicinity of the camp. The result was the battle of the Ia Drang valley, named for a small river that flowed through the area of operations. For thirty-five days the division pursued and fought the 32d, 33d, and 66th North Vietnamese Regiments, until the enemy, suffering heavy casualties, returned to his bases in Cambodia.

With scout platoons of its air cavalry squadron covering front and flanks, each battalion of the division's 1st Brigade established company bases from which patrols searched for enemy forces. For several days neither ground patrols nor aero-scouts found any trace but on 4 November the scouts spotted a regimental aid station several miles west of Plei Me. Quick reacting aero-rifle platoons converged on the site. Hovering above, the airborne scouts detected an enemy battalion nearby and attacked from UH-1B gunships with aerial rockets and machine guns. Operating beyond the range of their ground artillery, Army units engaged the enemy in an intense firefight. Again enemy troops "hugged" American forces, then broke contact as reinforcements began to arrive.

The search for the main body of the enemy continued for the next few days, with Army units concentrating their efforts in the vicinity of the Chu Pong Massif, a mountain near the Cambodian border that was believed to be an enemy base. Communist forces were given little rest, as patrols harried and ambushed them. The enemy attacked an American patrol base Landing Zone MARY, at night, but was repulsed by the first night air assault into a defensive perimeter under fire, accompanied by aerial rocket fire.

The heaviest fighting was yet to come. As the division began the second stage of its campaign, enemy forces began to move out of the Chu Pong base. Units of the 1st Cavalry Division advanced to establish artillery bases and landing zones at the base of the mountain. Landing Zone X-RAY was one of several U.S. positions vulnerable to attack by the enemy forces that occupied the surrounding high ground. Here on 14 November began fighting that pitted three battalions against elements of two NVA regiments. Withstanding repeated mortar attacks and infantry assaults, the Americans used every means of firepower available to them-the division's own gunships, massive artillery bombardment, hundreds of strafing and bombing attacks by tactical aircraft, and earth- shaking bombs dropped by B-52 bombers from Guam- to turn back a determined enemy. The Communists lost 600 dead, the Americans 79.

Although badly hurt, the enemy did not leave the Ia Drang valley. Elements of the 66th North Vietnamese Regiment moving east toward Plei Me encountered an American battalion on 17 November, a few miles north of X-RAY. The fight that resulted was a gory reminder of the North Vietnamese mastery of the ambush. The Communists quickly snared three U.S. companies in their net. As the trapped units struggled for survival,  nearly all semblance of organized combat disappeared in the confusion and mayhem, Neither reinforcements nor effective firepower could be brought in. At times combat was reduced to valiant efforts by individuals and small units to avert annihilation. When the fighting ended that night, 60 percent of the Americans were casualties, and almost one of every three soldiers in the battalion had been killed.

Lauded as the first major American triumph of the Vietnam War, the battle of the Ia Drang valley was in truth a costly and problematic victory. The airmobile division, committed to combat less than a month after it arrived in-country, relentlessly pursued the enemy for thirty-five days over difficult terrain and defeated three NVA regiments. In part, its achievements underlined the flexibility that Army divisions had gained in the early 1960's under the Reorganization Objective Army Division (ROAD) concept. Replacing the pentomic division with its five lightly armed battle groups, the ROAD division, organized around three brigades, facilitated the creation of brigade and battalion task forces tailored to respond and fight in a variety of military situations. The newly organized division reflected the Army's embrace of the concept of flexible response and proved eminently suitable for operations in Vietnam. The helicopter was given great credit as well. Nearly every aspect of the division's operations was enhanced by its airmobile capacity. Artillery batteries were moved sixty-seven times by helicopter. Intelligence, medical, and all manner of logistical support benefited as well from the speed and flexibility provided by helicopters. Despite the fluidity of the tactical situation, airmobile command and control procedures enabled the division to move and to keep track of its units over a large area, and to accommodate the frequent and rapid changes in command arrangements as units were moved from one headquarters to another.

Yet for all the advantages that the division accrued from airmobility, its performance was not without blemish. Though the conduct of division-size airmobile operations proved tactically sound, two major engagements stemmed from the enemy's initiative in attacking vulnerable American units. On several occasions massive air and artillery support provided the margin of victory (if not survival). Above all, the division's logistical self-sufficiency fell short of expectations. It could support only one brigade in combat at a time, for prolonged and intense operations consumed more fuel and ammunition than the division's helicopters and fixed-wing Caribou aircraft could supply. Air Force tactical airlift became necessary for resupply. Moreover, in addition to combat losses and damage, the division's helicopters suffered from heavy use and from the heat, humidity, and dust of Vietnam, taxing its maintenance capacity. Human attrition was also high; hundreds of soldiers, the equivalent of almost a battalion, fell victim to a resistant strain of malaria peculiar to Vietnam's highlands.  

Westmoreland's satisfaction in blunting the enemy's offensive was tempered by concern that enemy forces might re-enter South Vietnam and resume their offensive while the airmobile division recuperated at the end of November and during most of December. He thus requested immediate reinforcements from the Army's 25th Infantry Division, based in Hawaii and scheduled to deploy to South Vietnam in the spring of 1966. By the end of 1965, the division's 3d Brigade had been airlifted to the highlands and, within a month of its arrival, had joined elements of the 1st Cavalry Division to launch a series of operations to screen the border. Army units did not detect any major enemy forces trying to cross from Cambodia into South Vietnam. Each operation, however, killed hundreds of enemy soldiers and refined airmobile techniques, as Army units learned to cope with the vast territorial expanse and difficult terrain of the highlands.

In Operation MATADOR, for example, air strikes were used to blast holes in the forests, enabling helicopters to bring in heavy engineer equipment to construct new landing zones for use in future operations. Operation LINCOLN, a search and destroy operation on the Chu Pong Massif, featured combined armor and airmobile operations; air cavalry scouts guided armored vehicles of the 3d Brigade, 25th Infantry Division, as they operated in a lightly wooded area near Pleiku City. Also in LINCOLN, Army engineers, using heli-lifted equipment, in two days cleared and constructed a runway to handle C-130 air transports in an area inaccessible by road.

Despite the relative calm that followed the Ia Drang fighting, the North Vietnamese left no doubt of their intent to continue infiltration and to challenge American forces along the highland border. In February 1966 enemy forces overran the Special Forces camp at A Shau, in the remote northwest corner of I Corps. The loss of the camp had long-term consequences, enabling the enemy to make the A Shau valley a major logistical base and staging area for forces infiltrating into the piedmont and coastal areas. The loss also highlighted certain differences between operational concepts of the Army and the Marines. Concentrating their efforts in the coastal districts of I Corps and lacking the more extensive helicopter support enjoyed by Army units, the Marines avoided operations in the highlands. On the other hand, Army commanders in II Corps sought to engage the enemy as close to the border as possible and were quick to respond to threats to Special Forces camps in the highlands. Operations near the border were essential to Westmoreland's efforts to keep main force enemy units as far as possible from heavily populated areas.

For Hanoi's strategists, however, a reciprocal relation existed between highlands and coastal regions. Here, as in the south, the enemy directed his efforts to preserving his own influence among the population near the coast, from which he derived considerable support. At the same time, he maintained a constant military threat in the highlands to divert allied forces from efforts at pacification. Like the chronic shifting of units from the neighborhood of Saigon to the war zones in III Corps, the frequent movement of American units between coast and border in II Corps reflected the Communist desire to relieve allied military pressure whenever guerrilla and local forces were endangered. In its broad outlines, Hanoi's strategy to cope with U.S, forces was the same employed by the Viet Minh against the French and by Communist forces in 1964 and 1965 against the South Vietnamese Army. Whether it would be equally successful remained to be seen.

The airmobile division spent the better part of the next two years fighting Viet Cong and NVA main force units in the coastal plain and piedmont valleys of Binh Dinh Province. Here the enemy had deep roots, while pacification efforts were almost dead. Starting in early 1966, the 1st Cavalry Division embarked on a series of operations against the 2d Viet Cong and the 18th and 22d North Vietnamese Regiments of the 3d North Vietnamese Division (the Yellow Star Division). For the most part, the 1st Cavalry Division operated in the Bong Son plain and the adjacent hills, from which enemy units reinforced the hamlet and village guerrillas who gathered in taxes, food, and recruits. As in the highlands, the division exploited its airmobility, using helicopters to establish positions in the upper reaches of the valleys. They sought to flush the enemy from his hiding places and drive him toward the coast, where American, South Vietnamese, and South Korean forces held blocking positions. When trapped, the enemy was attacked by ground, naval, and air fire, The scheme was a new version of an old tactical concept, the "hammer and anvil," with the coastal plain and the natural barrier formed by the South China Sea forming the anvil or killing zone. Collectively the operations became known as the Binh Dinh Pacification Campaign.

For forty-two days elements of the airmobile division scoured the An Lao and Kim Son valleys, pursuing enemy units that had been surprised and routed from the Bong Son plain. Meanwhile, Marine forces in neighboring Quang Ngai Province in southern I Corps sought to bar the enemy's escape routes to the north. The enemy units evaded the Americans, but thousands of civilians Red from the Viet Cong-dominated valleys to government. controlled areas. Although the influx of refugees taxed the government's already strained relief services, the exodus of peasants weakened the Viet Cong's infrastructure and aimed a psychological blow at the enemy's prestige. The Communists had failed either to confront the Americans or to protect the population over which they had gained control.

Failing to locate the fleeing enemy in the An Lao valley, units of the airmobile division assaulted another enemy base area, a group of valleys and ridges southwest of the Bong Son plain known as the Crow's Foot or the Eagle's Claw. Here some Army units sought to dislodge the enemy from his upland bases while others established blocking positions at the "toe" of each valley, where it found outlet to the plain. In six weeks over 1,300 enemy soldiers were killed. Enemy forces in northern Binh Dinh Province were temporarily thrown off balance. Beyond this, the long-term effects of the operation were unclear. The 1st Cavalry Division did not stay in one area long enough to exploit its success. Whether the Saigon government could marshal its forces effectively to provide local security and to reassert its political control remained to be seen.

Later operations continued to harass an elusive foe. Launching a new attack without the extensive preparatory reconnaissance that often alerted the enemy, Army units again surprised him in the Bong Son area but soon lost contact. The next move was against an enemy build-up in the vicinity of the Vinh Thanh Special Forces Camp. Here the Green Berets watched the "Oregon Trail," an enemy infiltration corridor that passed through the Vinh Thanh valley from the highlands to the coast. Forestalling the attack, Army units remained in the area where they conducted numerous patrols and made frequent contact with the enemy. (One U.S. company came close to being overrun in a ferocious firefight.) But again the action had little enduring effect, except to increase the enemy's caution by demonstrating the airmobile division's agility in responding to a threat.

After a brief interlude in the highlands, the division returned to Binh Dinh Province in September 1966. Conditions in the Bong Son area differed little from those the division had first encountered. For the most part, the Viet Cong rather than the Saigon government had been successful in reasserting their authority, and pacification was at a standstill. The division devoted most of its resources for the remainder of 1966 and throughout 1967 to supporting renewed efforts at pacification. In the fall of 1966, for the first time in a year, all three of the division's brigades were reunited and operating in Binh Dinh Province. Although elements of the division were occasionally transferred to the highlands as the threat there waxed and waned, the general movement of forces was toward the north. Army units increasingly were sent to southern I Corps during 1967, replacing Marine units in operations similar to those in Binh Dinh Province.

In one such operation the familiar pattern of hammer and anvil was tried anew, with some success. The 1st Cavalry Division opened with a multibattalion air assault in an upland valley to flush the enemy toward the coast, where allied ground and naval forces were prepared to bar his escape. Enemy forces had recently left their mountain bases to plunder the rice harvest and to harass South Vietnamese forces providing security for provincial elections. These units were caught with their backs to the sea. For most of October, allied forces sought to destroy the main body of a Communist regiment isolated on the coast and to seize an enemy base in the nearby Phu Cat Mountain. The first phase consisted of several sharp combat actions near the coastal hamlet of Hoa Hoi. With South Vietnamese and U.S. naval forces blocking an escape by sea, the encircled enemy fought desperately to return to the safety of his bases in the upland valleys. His plight was compounded when floods forced his troops out of their hiding places and exposed them to attacks. After heavy losses, remnants of the regiment divided into small parties that escaped through allied lines. As contacts with the enemy diminished on the coast, American efforts shifted inland, with several sharp engagements occurring when enemy forces tried to delay pursuit or to divert the allies from entering base areas. By the end of October, as the Communists retreated north and west, the running fight had accounted for over 1,000 enemy killed. Large caches of supplies, equipment, and food were uncovered, and the Viet Cong's shadow government in some coastal hamlets and villages was severely damaged, some hamlets reverting to government control for the first time in several years.

Similar operations continued through 1967 and into early 1968. In addition to offensive operations against enemy main forces, Army units in Binh Dinh worked in close co-ordination with South Vietnamese police, Regional and Popular Forces, and the South Vietnamese Army to help the Saigon government gain a foothold in villages and hamlets dominated or contested by the Communists. The 1st Cavalry Division adopted a number of techniques in support of pacification. Army units frequently participated in cordon and search operations: airmobile forces seized positions around a hamlet or village at dawn to prevent the escape of local forces or cadres while South Vietnamese authorities undertook a methodical house-to-house search. The Vietnamese checked the legal status of residents, took a census, and interrogated suspected Viet Cong to obtain more information about the enemy's local political and military apparatus. At the same time, allied forces engaged in a variety of civic action and psychological operations; specially trained pacification cadres established the rudiments of local government and provided various social and economic services. At other times, the division might participate in "checkpoint and snatch" operations, establishing surprise roadblocks and inspecting traffic on roads frequented by the insurgents.

Although much weakened by such methods, enemy forces found opportunities to attack American units. They aimed both to win a military victory and to remind the local populace of their presence and power. An attack on Landing Zone BIRD, an artillery base on the Bong Son plain, was one such example. Taking advantage of the Christmas truce of 1966, enemy units moved into position and mounted a ferocious attack as soon as the truce ended. Although portions of the base were overrun, the onslaught was checked when artillerymen leveled their guns and fired Beehive antipersonnel rounds directly into the waves of oncoming enemy troops. Likewise, several sharp firefights occurred immediately after the 1967 Tet truce, when the enemy took advantage of the cease-fire to move back among the population. This time units of the 1st Cavalry Division forced the enemy to leave the coastal communities and seek refuge in the piedmont. As the enemy moved across the boundary into southern I Corps, so too did units of the airmobile division. About a month later, the 3d Brigade, 25th Infantry Division, also moved to southern I Corps. Throughout the remainder of 1967, other Army units transferred to either I Corps to reinforce the marines or to the highlands to meet renewed enemy threats. As the strength of American units committed to the Binh Dinh Pacification Campaign decreased during late 1967 and early 1968, enemy activity in the province quickened as the Viet Cong sought to reconstitute their weakened military forces and to regain a position of influence among the local population.

In many respects, the Binh Dinh campaign was a microcosm of Westmoreland's over-all campaign strategy. It showed clearly the intimate relation between the war against enemy main force units and the fight for pacification waged by the South Vietnamese, and it demonstrated the effectiveness of the airmobile concept. After two years of persistent pursuit of the NVA's Yellow Star Division, the 1st Cavalry Division had reduced the combat effectiveness of each of its three regiments. By the end of 1967, the threat to Binh Dinh Province posed by enemy main force units had been markedly reduced. The airmobile division's operations against the 3d North Vietnamese Division, as well as its frequent role in operations directly in support of pacification, had weakened local guerrilla forces and created an environment favorable to pacification.

The campaign in Binh Dinh also exposed the vulnerabilities of Westmoreland's campaign strategy. Despite repeated defeats at the hands of the Americans, the three NVA regiments still existed. They contrived to find respite and a measure of rehabilitation, building their strength anew with recruits filtering down from the North, with others found in-country, and with Viet Cong units consolidated into their ranks. Although much weakened, Communist forces persistently returned to areas cleared by the 1st Cavalry Division. Even more threatening to the allied cause, Saigon's pacification efforts languished as South Vietnamese forces failed in many instances to provide security to the villages and effective police action to root out local Viet Cong cadres. And the government, dealing with a population already skeptical, failed to grant the political, social, and economic benefits it had promised.

The Highlands: Progress or Stalemate?

Moreover, the allies could not concentrate their efforts everywhere as they had in strategic Binh Dinh. The expanse of the highlands compelled Army operations there to be carried out with economy of force. During 1966 and 1967, the Americans engaged in a constant search for tactical concepts and techniques to maximize their advantages of firepower and mobility and to compensate for the constraints of time, distance, difficult terrain, and an inviolable border. Here the war was fought primarily to prevent the incursion of NVA units into South Vietnam and to erode their combat strength. In the highlands, each side pursued a strategy of military confrontation, seeking to weaken the fighting forces and will of its opponent through attrition. Each sought military victories to convince opposing leaders of the futility of continuing the contest. For the North Vietnamese, however, confrontation in the highlands had the additional purpose of relieving allied pressure in other areas, where pacification jeopardized their hold on the rural population. Of all the factors influencing operations in the highlands, the most significant may well have been the strength and success of pacification elsewhere.

For Americans, the most difficult problem was to locate the enemy. Yet Communist strategists sometimes created threats to draw in the Americans.

Recurrent menaces to Special Forces camps reflected the enemy's seasonal cycle of operations, his desire to harass and eliminate such camps, and his hope of luring allied forces into situations where he held the military advantages. Thus Army operations in the highlands during 1966 and 1967 were characterized by wide- ranging, often futile searches, punctuated by sporadic but intense battles fought usually at the enemy's initiative.

For the first few months of 1966, the Communists lay low. In May, however, a significant concentration of enemy forces appeared in Pleiku and Kontum Provinces. The 1st Brigade, 101st Airborne Division, the reserve of I Field Force, was summoned to Pleiku and subsequently moved to Dak To, a CIDG camp in northern Kontum Province, to assist a besieged South Vietnamese force at the nearby government post at Toumorong. Although the 24th North Vietnamese Regiment had surrounded Toumorong, allied forces secured the road to Dak To and evacuated the government troops, leaving one battalion of the 101st inside the abandoned camp and one company in an exposed defensive position in the jungle a short distance beyond. On the night of 6 June a large North Vietnamese force launched repeated assaults on this lone company. Facing disaster, the commander called in air strikes on his own position to stop the enemy's human-wave attacks. Relief arrived the next morning, as additional elements of the brigade were heli-lifted to the battlefield to pursue and trap the North Vietnamese. Fighting to close off the enemy's escape routes, the Americans called in renewed air strikes, including B-52's. By 20 June enemy resistance had ended, and the NVA regiment that had begun the fighting, leaving behind dead, escaped to the safety of its Laotian base.

Although the enemy's push in Kontum Province was blunted, the siege of Toumorong was only one aspect of his summer offensive in the highlands. Suspecting that NVA forces meant to return to the Ia Drang, Westmoreland sent the 3d Brigade, 25th Infantry Division, back into the valley in May. Dividing the area into "checkerboard" squares, the brigade methodically searched each square. Small patrols set out ambushes and operated for several days without resupply to avoid having helicopters reveal their location. After several days in one square, the patrols leapfrogged by helicopter to another. Though the Americans made only light, sporadic contacts, the cumulative toll of enemy killed was equal to many short, violent battles. One significant contact was made in late May near the Chu Pong Massif. A running battle ensued, as the enemy again sought safety in Cambodia. Westmoreland now appealed to Washington for permission to maneuver Army units behind the enemy, possibly into Cambodian territory. But officials refused, fearing international repercussions, and the NVA sanctuary remained inviolate.

Yet the operation confirmed that sizable enemy forces had returned to South Vietnam and, as in the fall of 1965, were threatening the outposts at Plei Me and Duc Co. To meet the renewed threat, I Field Force sent additional Army units to Pleiku Province and launched a new operation under the 1st Cavalry Division. The action followed the now familiar pattern of extensive heli-lifts, establishment of patrol bases, and intermittent contact with an enemy who usually avoided American forces. When the Communists elected to fight, they preferred to occupy high ground; dislodging them from hilltop bunkers was a difficult task, requiring massive air and artillery support. By the time the enemy left Pleiku again at the end of August, his forces had incurred nearly 500 deaths.

Border battles continued, however, and some were sharp. When enemy forces appeared in strength around a CIDG camp at Plei Djering in October, elements of the 4th Infantry and 1st Cavalry Divisions rapidly reinforced the camp, clashing with the enemy in firefights during October and November. As North Vietnamese forces began to withdraw through the Plei Trap valley, the 1st Brigade, 101st Airborne Division, was airlifted from Phu Yen to northern Kontum to try to block their escape, but failed to trap them before they reached the border. Army operations in the highlands were continued by the 4th Infantry Division. In addition to screening the border to detect infiltration, the division constructed a new road between Pleiku and the highland outpost at Plei Djering and helped the Saigon government resettle thousands of Montagnards in secure camps. Contact with the enemy generally was light, the heaviest occurring in mid- February 1967, in an area west of the Nam Sathay River near the Cambodian border, when Communist forces unsuccessfully tried to overrun several American fire bases. Despite infrequent contacts, however, 4th Division troops killed 700 enemy over a period of three months.

In I Corps as well, the enemy seemed intent on dispersing American forces to the border regions. Heightened activity along the demilitarized zone drew marines from southern I Corps. To replace them, Army units were transferred from III and II Corps to the area vacated by the marines, among them the 196th Infantry Brigade, which was pulled out of Operation JUNCTION CITY, and the 3d Brigade, 25th Infantry Division, which had been operating in the II Corps Zone. Together with the 1st Brigade, 101st Airborne Division, these units formed Task Force OREGON, activated on 12 April 1967 and placed under the operational control of the III Marine Amphibious Force. Army infantry units were now operating in all four of South Vietnam's corps areas.

Once at Chu Lai, the Army forces supported an extensive South Vietnamese pacification effort in Quang Tin Province. To the north, along the demilitarized zone, Army heavy artillery engaged in almost daily duels with NVA guns to the north. In Quang Tri Province, the marines fought a hard twelve-day battle to prevent NVA forces from dominating the hills surrounding Khe Sanh. The enemy's heightened military activity along the demilitarized zone, which included frontal attacks across it, prompted American officials to begin construction of a barrier consisting of highly sophisticated electronic and acoustical sensors and strong point defenses manned by allied forces. Known as the McNamara Line, after Secretary of Defense Robert S. McNamara, who vigorously promoted the concept, the barrier was to extend across South Vietnam and eventually into Laos. Westmoreland was not enthusiastic about the project, for he hesitated to commit large numbers of troops to man the strongpoints and doubted that the barrier would prevent the enemy from breaching the demilitarized zone. Hence the McNamara Line was never completed.

Throughout the summer of 1967, Marine forces endured some of the most intense enemy artillery barrages of the war and fought several battles with NVA units that infiltrated across the 17th parallel. Their stubborn defense, supported by massive counterbattery fire, naval gunfire, and air attacks, ended the enemy's offensive in northern I Corps, but not before Westmoreland had to divert additional Army units as reinforcements. A brigade of the 1st Cavalry Division and South Korean units were deployed to southern I Corps to replace additional marines who had been shifted further north. The depth of the Army's commitment in I Corps was shown by Task Force OREGON's reorganization as the 23d Infantry Division (Americal). The only Army division to be formed in South Vietnam, its name echoed a famous division of World War II that had also been organized in the Pacific. If the enemy's aim was to draw American forces to the north, he evidently was succeeding.

Even as Westmoreland shifted allied forces from II Corps to I Corps, fighting intensified in the highlands. After Army units made several contacts with enemy forces during May and June, Westmoreland moved the 173d Airborne Brigade from III Corps to II Corps to serve as the I Field Force's strategic reserve. Within a few days, however, the brigade was committed to an effort to forestall enemy attacks against the CIDG camps of Dak To, Dak Seang, and Dak Pek in northern Kontum Province. Under the control of the 4th Infantry Division, the operation continued throughout the summer until the enemy threat abated. A few months later, however, reconnaissance patrols in the vicinity of Dak To detected a rapid and substantial build-up of enemy forces in regimental strength. Believing an attack to be imminent,4th Infantry Division forces reinforced the garrison. In turn, the 173d Airborne Brigade returned to the highlands, arriving on 2 November. From 3 to 15 November enemy forces estimated to number 12,000 probed, harassed, and attacked American and South Vietnamese positions along the ridges and hills surrounding the camp. As the attacks grew stronger, more U.S. and South Vietnamese reinforcements were sent, including two battalions from the airmobile division and six ARVN battalions. By mid-November allied strength approached 8,000.

Despite daily air and artillery bombardments of their positions, the North Vietnamese launched two attacks against Dak To on 15 November, destroying two C-130 aircraft and causing severe damage to the camp's ammunition dump. Allied forces strove to dislodge the enemy from the surrounding hills, but the North Vietnamese held fast in fortified positions. The center of enemy resistance was Hill 875; here, two  battalions of the 173d Airborne Brigade made a slow and painful ascent against determined resistance and under grueling physical conditions, fighting for every foot of ground. Enemy fire was so intense and accurate that at times the Americans were unable to bring in reinforcements by helicopter or to provide fire support. In fighting that resembled the hill battles of the final stage of the Korean War, the confusion at Dak To pitted soldier against soldier in classic infantry battle. In desperation, beleaguered U.S. commanders on Hill 875 called in artillery and even B-52 air strikes at perilously close range to their own positions. On 17 November American forces at last gained control of Hill 875.

The battle of Dak To was the longest and most violent in the highlands since the battle of the Ia Drang two years before. Enemy casualties numbered in the thousands, with an estimated 1,400 killed. Americans had suffered too. Approximately one- fifth of the 173d Airborne Brigade had become casualties, with 174 killed, 642 wounded, and 17 missing in action. If the battle of the Ia Drang exemplified airmobility in all its  versatility, the battle of Dak To, with the arduous ascent of Hill 875, epitomized infantry combat at its most basic and the crushing effect of supporting air power.

Yet Dak To was only one of several border battles in the waning months of 1967. At Song Be and Loc Ninh in III Corps, and all along the northern border of I Corps, the enemy exposed his positions in order to confront U.S. forces in heavy fighting. By the end of 1967 the 1st Infantry Division had again concentrated near the Cambodian border, and the 25th Infantry Division had returned to War Zone C. The enemy's threat in I Corps caused Westmoreland to disperse more Army units. In the vacuum left by their departure, local Viet Cong sought to reconstitute their forces and to reassert their control over the rural population. In turn, Viet Cong revival often was a prelude to the resurgence of Communist military activity at the district and village level. Hard pressed to find additional Army units to shift from III Corps and II Corps to I Corps, Westmoreland asked the Army to accelerate deployment of two remaining brigades of the 101st Airborne Division from the United States. Arriving in December 1967, the brigades were added to the growing number of Army units operating in the northern provinces.

While allied forces were under pressure, the border battles of 1967 also led to a reassessment of strategy in Hanoi. Undeviating in their long-term aim of unification, the leaders of North Vietnam recognized that their strategy of military confrontation had failed to stop the American military build-up in the South or to reduce U.S. military pressure on the North. The enemy's regular and main force units had failed to inflict a salient military defeat on American forces. Although the North Vietnamese Army maintained the tactical initiative, Westmoreland had kept its units at bay and in some areas, like Binh Dinh Province, diminished their influence on the contest for control of the rural population. Many Communist military leaders perceived the war to be a stalemate and thought that continuing on their present course would bring diminishing returns, especially if their local forces were drastically weakened.

On the other side, Westmoreland could rightly point to some modest progress in improving South Vietnam's security and to punishing defeats inflicted on several NVA regiments and divisions. Yet none of his successes were sufficient to turn the tide of the war. The Communists had matched the build-up of American combat forces, the number of enemy divisions in the South increasing from one in early 1965 to nine at the start of 1968. Against 320 allied combat battalions, the North Vietnamese and Viet Cong could marshal 240. Despite heavy air attacks against enemy lines of infiltration, the flow of men from the North had continued unabated, even increasing toward the end of 1967.

Although the Military Assistance Command had succeeded in warding off defeat in 1965 and had gained valuable time for the South Vietnamese to concentrate their political and military resources on pacification, security in many areas of South Vietnam had improved little. Americans noted that the Viet Cong, in one district within artillery range of Saigon, rarely had any unit as large as a company. Yet, relying on booby traps,  mines, and local guerrillas, they tied up over 6,000 American and South Vietnamese troops. More and more, success in the South seemed to depend not only on Westmoreland's ability to hold off and weaken enemy main force units, but on the equally important efforts of the South Vietnamese Army, the Regional and the Popular Forces, and a variety of paramilitary and police forces to pacify the countryside. Writing to President Johnson in the spring of 1967, outgoing Ambassador Henry Cabot Lodge warned that if the South Vietnamese "dribble along and do not take advantage of the success which MACV has achieved against the main force and the Army of North Viet-Nam, we must expect that the enemy will lick his wounds, pull himself together and make another attack in '68." Westmoreland's achievements, he added, would be "judged not so much on the brilliant performance of the U.S. troops as on the success in getting ARVN, RF and PF quickly to function as a first-class ... counter-guerrilla force." Meanwhile the war appeared to be in a state of equilibrium. Only an extraordinary effort by one side or the other could bring a decision.

The Tet Offensive

The Tet offensive marked a unique stage in the evolution of North Vietnam's People's War. Hanoi's solution to the stalemate in the South was the product of several factors. North Vietnam's large unit war was unequal to the task of defeating American combat units. South Vietnam was becoming politically and militarily stronger, while the Viet Cong's grip over the rural population eroded. Hanoi's leaders suspected that the United States, frustrated by the slow pace of progress, might intensify its military operations against the North. (Indeed, Westmoreland had broached plans for an invasion of the North when he appealed for additional forces in 1967.) The Tet offensive was a brilliant stroke of strategy by Hanoi, designed to change the arena of war from the battlefield to the negotiating table, and from a strategy of military confrontation to one of  talking and fighting.

Communist plans called for violent, widespread, simultaneous military actions in rural and urban areas throughout the South-a general offensive. But as always, military action was subordinate to a larger political goal. By focusing attacks on South Vietnamese units and facilities, Hanoi sought to undermine the morale and will of Saigon's forces. Through a collapse of military resistance, the North Vietnamese hoped to subvert public confidence in the government's ability to provide security, triggering a crescendo of popular protest to halt the fighting and force a political accommodation. In short, they aimed at a general uprising. Hanoi's generals, however, were not completely confident that the general offensive would succeed. Viet Cong forces, hastily reinforced with new recruits and part-time guerrillas, bore the brunt. Except in the northern provinces, the North Vietnamese Army stayed on the sidelines, poised to exploit success. While hoping to spur negotiations, Communist leaders probably had the more modest goals of reasserting Viet Cong influence and undermining Saigon's authority so as to cast doubt on its credibility as the United States' ally, In this respect, the offensive was directed toward the United States and sought to weaken American confidence in the Saigon government, discredit Westmoreland's claims of progress, and strengthen American antiwar sentiment.  Here again, the larger purpose was to bring the United States to the negotiating table and hasten American disengagement from Vietnam.

The Tet offensive began quietly in mid-January 1968 in the remote northwest corner of South Vietnam. Elements of three NVA divisions began to mass near the Marine base at Khe Sanh. At first the ominous proportions of the build-up led the Military Assistance Command to expect a major offensive in the northern provinces. To some observers the situation at Khe Sanh resembled Dien Bien Phu, the isolated garrison where the Viet Minh had defeated French forces in 1954. Khe Sanh, however, was a diversion, an attempt to entice Westmoreland to defend yet another border post by withdrawing forces from the populated areas of the South.

While pressure around Khe Sanh increased, 85,000 Communist troops prepared for the Tet offensive. Since the fall of 1967, the enemy had been infiltrating arms, ammunition, and men, including entire units, into Saigon and other cities and towns. Most of these meticulous preparations went undetected, although MACV received warnings of a major enemy action to take place in early 1968. The command did pull some Army units closer to Saigon just before the attack. However, concern over the critical situation at Khe Sanh and preparations for the Tet holiday festivities preoccupied most Americans and South Vietnamese. Even when Communist forces prematurely attacked Kontum, Qui Nhon, Da Nang, and other towns in the northern and central provinces on 29 January, Americans were unprepared for what followed.

On 31 January combat erupted throughout the entire country. Thirty-six of 44 provincial capitals and 64 of 242 district towns were attacked, as well as 5 of South Vietnam's 6 autonomous cities, among them Hue and Saigon. Once the shock and confusion wore off, most attacks were crushed in a few days. During those few days, however, the fighting was some of the most violent ever seen in the South or experienced by many ARVN units. Though the South Vietnamese were the main target, American units were swept into the turmoil. All Army units in the vicinity of Saigon helped to repel Viet Cong attacks there and at the nearby logistical base of Long Binh. In some American compounds, cooks, radiomen, and clerks took up arms in their own defense. Military police units helped root the Viet Cong out of Saigon, and Army helicopter gunships were in the air almost continuously, assisting the allied forces.

The most tenacious combat occurred in Hue, the ancient capital of Vietnam, where the 1st Cavalry and 101st Airborne Divisions, together with Marines and South Vietnamese forces, participated in the only extended urban combat of the war. Hue had a tradition of Buddhist activism, with overtones of neutralism, separatism, and anti-Americanism, and Hanoi's strategists thought that here if anywhere the general offensive-general uprising might gain a political foothold. Hence they threw North Vietnamese regulars into the battle, indicating that the stakes at Hue were higher than elsewhere in the South. House-to-house and street-to-street fighting caused enormous destruction, necessitating massive reconstruction and community assistance programs after the battle. The allies took three weeks to recapture the city. The slow, hard-won gains of 1967 vanished overnight as South Vietnamese and Marine forces were pulled out of the countryside to reinforce the city.

Yet throughout the country the South Vietnamese forces acquitted themselves well, despite high casualties and many desertions. Stunned by the attacks, civilian support for the Thieu government coalesced instead of weakening. Many Vietnamese for whom the war had been an unpleasant abstraction were outraged. Capitalizing on the new feeling, South Vietnam's leaders for the first time dared to enact general mobilization. The change from grudging toleration of the Viet Cong to active resistance provided an opportunity to create new local defense organizations and to attack the Communist infrastructure. Spurred by American advisers, the Vietnamese began to revitalize pacification. Most important, the Viet Cong suffered a major military defeat, losing thousands of experienced combatants and seasoned political cadres, seriously weakening the insurgent base in the South.

Americans at home saw a different picture. Dramatic images of the Viet Cong storming the American Embassy in the heart of Saigon and the North Vietnamese Army clinging tenaciously to Hue obscured Westmoreland's assertion that the enemy had been defeated. Claims of progress in the war, already greeted with skepticism, lost more credibility in both public and official circles. The psychological jolt to President Johnson's  Vietnam policy was redoubled when the military requested an additional 206,000 troops. Most were intended to reconstitute the strategic reserve in the United States, exhausted by Westmoreland's appeals for combat units between 1965 and 1967. But the magnitude of the new request, at a time when almost a half- million U.S. troops were already in Vietnam, cast doubts on the conduct of the war and prompted a reassessment of American policy and strategy.

Without mobilization, the United States was overcommitted. The Army could send few additional combat units to Vietnam without making deep inroads on forces destined for NATO or South Korea. The dwindling strategic reserve left Johnson with fewer options in the spring of 1968 than in the summer of 1965. His problems were underscored by heightened international tensions when North Korea captured an American naval vessel, the USS Pueblo, a week before the Tet offensive; by Soviet armed intervention in Czechoslovakia in the summer of 1968; and by chronic crises in the Mideast. In addition, Army units in the United States were needed often between 1965 and 1968 to enforce federal civil rights legislation and to restore public order in the wake of civil disturbances.

Again, as in 1967, Johnson refused to sanction a major troop levy, but he did give Westmoreland some modest reinforcements to bolster the northern provinces. Again tapping the strategic reserve, the Army sent him the 3d Brigade, 82d Airborne Division, and the 1st Brigade, 5th Infantry Division, (Mechanized)-the last Army combat units to deploy to South Vietnam. In addition, the President called to active duty a small number of Reserve units, totaling some 40,000 men, for duty in Southeast Asia and South Korea, the only use of Reserves during the Vietnam War. For Westmoreland, Johnson's decision meant that future operations would have to make the best possible use of American forces, and that the South Vietnamese Army would have to shoulder a larger share of the war effort. The President also curtailed air strikes against North Vietnam to spur negotiations. Finally, on 31 March Johnson announced his decision not to seek re-election in order to give his full attention to the goal of resolving the conflict. Hanoi had suffered a military defeat, but had won a  political and diplomatic victory by shifting American policy toward disengagement.

For the Army the new policy meant a difficult time. In South Vietnam, as in the United States, its forces were stretched thin. The Tet offensive had concentrated a large portion of the combat forces in I Corps, once a Marine preserve. A new command, the XXIV Corps, had to be activated at Da Nang, and Army logistical support, previously confined to the three southern corps zones, extended to the five northern provinces as  well. While Army units reinforced Hue and the demilitarized zone, the marines at Khe Sanh held fast. Enemy pressure on the besieged base increased daily, but the North Vietnamese refrained from an all-out attack, still hoping to divert American forces from Hue. Recognizing that he could ill afford Khe Sanh's defense, Westmoreland decided to subject the enemy to the heaviest air and artillery bombardment of the war. His tactical gamble succeeded; the enemy withdrew, and the Communist offensive slackened. The enemy nevertheless persisted in his effort to weaken the Saigon government, launching nationwide "mini-Tet" offensives in May and August Pockets of heavy fighting occurred throughout the south, and Viet Cong forces again tried to infiltrate into Saigon-the last gasps of the general offensive- general uprising. Thereafter enemy forces generally dispersed and avoided contact with Americans. In turn, the allies withdrew from Khe Sanh itself in the summer of 1968. Its abandonment signaled the demise of the McNamara Line and further postponement of MACV's hopes for large-scale American cross- border operations. For the remainder of 1968, Army units in I Corps were content to help restore security around Hue and other coastal areas, working closely with the marines and the South Vietnamese in support of pacification. North Vietnamese and Viet Cong forces generally avoided offensive operations. As armistice negotiations began in Paris, both sides prepared to enter a new phase of the war.

Vietnamization

The last phase of American involvement in South Vietnam was carried out under a broad policy called Vietnamization. Its main goal was to create strong, largely self-reliant South Vietnamese military forces, an objective consistent with that espoused by U.S. advisers as early as the 1950's. But Vietnamization also meant the withdrawal of a half-million American soldiers. Past efforts to strengthen and modernize South Vietnam's Army had proceeded at a measured pace, without the pressure of diminishing American support, large-scale combat, or the presence of formidable North Vietnamese forces in the South. Vietnamization entailed three overlapping phases: redeployment of American forces and the assumption of their combat role by the South Vietnamese; improvement of ARVN's combat and support capabilities, especially firepower and mobility; and replacement of the Military Assistance Command by an American advisory group. Vietnamization had the added dimension of fostering political, social, and economic reforms to create a vibrant South Vietnamese state based on popular participation in national political life. Such reforms, however, depended on progress in the pacification program which never had a clearly fixed timetable.

The task of carrying out the military aspects of Vietnamization fell to General Creighton W. Abrams, who succeeded General Westmoreland as MACV commander in mid-1968, when the latter returned to the United States to become Chief of Staff of the Army. Although he had the aura of a blunt, hard-talking, World War II tank commander, Abrams had spent two years as Westmoreland's deputy, working closely with South Vietnamese commanders. Like Westmoreland before him, Abrams viewed the military situation after Tet as an opportunity to make gains in pacifying rural areas and to reduce the strength of Communist forces in the South. Until the weakened Viet Cong forces could be rebuilt or replaced with NVA forces, both guerrilla and regular Communist forces had adopted a defensive posture. Nevertheless, 90,000 NVA forces were in the South, or in border sanctuaries, waiting to resume the offensive at a propitious time.

Abrams still had strong American forces; indeed, they reached their peak strength of 543,000 in March 1969. But he was also under pressure from Washington to minimize casualties and to conduct operations with an eye toward leaving the South Vietnamese in the strongest possible military position when U.S. forces withdrew. With these considerations in mind, Abrams decided to disrupt and destroy the enemy's bases, especially those near the border, to prevent their use as staging areas for offensive operations. His primary objective was the enemy's logistical support system rather than enemy main combat forces. At the same time, to enhance Saigon's pacification efforts and improve local security, Abrams intended to emphasize small unit operations, with extensive patrolling and ambushes, aiming to reduce the enemy's base of support among the rural  population.

To the greatest extent possible, he planned to improve ARVN's performance by conducting combined operations with American combat units. As the South Vietnamese Army assumed the lion's share of combat, it was expected to shift operations to the border and to assume a role similar to that performed by U.S. forces between 1965 and 1969. The Regional and Popular , Forces, in turn, were to take over ARVN's role in area security and pacification support, while the newly organized People's Self- Defense Force took on the task of village and hamlet defense. Stressing the close connection between combat and pacification operations, the need for co-operation between American and South Vietnamese forces, and the importance of coordinating all echelons of Saigon's armed forces, Abrams propounded a "one war" concept.

Yet even in his emphasis on combined operations and American support of pacification, Abrams' strategy had strong elements of continuity with Westmoreland's. For the first, operations in War Zones C and D in 1967 and the thrust into the A Shau valley in 1968 were ample precedents. Again, Westmoreland had laid the foundation for a more extensive U.S. role in pacification in 1967 by establishing Civil Operations Rural Development Support (CORDS). Under CORDS, the Military Assistance Command took charge of all American activities, military and civilian, in support of pacification. Abrams' contribution was to enlarge the Army's role. Under him, the U.S. advisory effort at provincial and district levels grew as the territorial forces gained in importance, and additional advisers were assigned to the Phoenix program, a concerted effort to eliminate the Communist political apparatus. Numerous mobile advisory teams helped the South Vietnamese Army and paramilitary forces to become adept in a variety of combat and support functions.

Despite all efforts, many Americans doubted whether Saigon's armed forces could successfully play their enlarged role under Vietnamization. Earlier counterinsurgency efforts had languished under less demanding circumstances, and Saigon's forces continued to be plagued with high desertions, spotty morale, and shortages of high quality leaders. Like the French before them, U.S. advisers had assumed a major role in providing and
coordinating logistical and firepower support, leaving the Vietnamese inexperienced in the conduct of large combined-arms operations. Despite the Viet Cong's weakened condition, South Vietnamese forces also continued to incur high casualties.

Similarly, pacification registered ostensible gains in rural security and other measures of progress, but such improvements of ten obscured its failure to establish deep roots. The Phoenix program, despite its success in seizing low-level cadres, rarely caught hard-core, high-level party officials, many of whom survived, as they had in the mid-1950's, by taking more stringent security measures. Furthermore, the program was abused by some South Vietnamese officials, who used it as a vehicle for personal vendettas. Saigon's efforts at political, social, and economic reform likewise were susceptible to corruption, venality, and nepotism. Temporary social and economic benefits for the peasantry rested on an uncertain foundation of  continued American aid, as did South Vietnam's entire economy and war effort.

Influencing all parts of the struggle was a new defense policy enunciated by Richard M. Nixon, who became President in January 1969. The "Nixon Doctrine" harkened back to the precepts of the New Look, placing greater reliance on nuclear retaliation, encouraging allies to accept a larger share of their own defense burden, and barring the use of U.S. ground forces in limited wars in Asia, unless vital national interests were at stake. Under this policy, American ground forces in South Vietnam, once withdrawn, were unlikely to return. For President Thieu in Saigon, the future was inauspicious. For the time being, large numbers of American forces were still present to bolster his country's war effort; what would happen when they departed, no one knew.

Military Operations, 1968-1969

Vietnamization began in earnest when two brigades of the U.S. Army's 9th Infantry Division left South Vietnam in July 1968, making the South Vietnamese Army responsible for securing the southern approaches to Saigon. The protective area that Westmoreland had developed around the capital was still intact. Allied forces engaged in a corps-wide counteroffensive to locate and destroy remnants of the enemy units that had participated in the Tet offensive, combining thousands of small unit operations, frequent sweeps through enemy bases, and persistent screening of the Cambodian border to prevent enemy main force units from returning. As the Military Assistance Command anticipated, the Communists launched a Tet offensive in 1969, but a much weaker one than a year earlier. Allied forces easily suppressed the outbreaks. Meanwhile, in critical areas around Saigon pacification had begun to take hold. Such signs of progress probably resulted mainly from the attrition of Viet Cong forces during Tet 1968. But the vigilant screening of the border contributed to the enemy's difficulty in reaching and helping local insurgent forces.

Yet Saigon was not impregnable. With increasing frequency, enemy sappers penetrated close enough to launch powerful rocket attacks against the capital. Such incidents terrorized civilians, caused military casualties, and were a violent reminder of the government's inability to protect the population. Sometimes simultaneous attacks were conducted throughout the country. An economy-of-force measure, the attacks brought little risk to the enemy and compelled allied forces to suspend other tasks while they cleared the "rocket belts" around every major urban center and base in the country,

In the Central Highlands the war of attrition continued. Until its redeployment of 1970, the Army protected major highland population centers and kept open important interior roads. Special Forces worked with the tribal highlanders to detect infiltration and harass enemy secret zones. As in the past, highland camps and outposts were a magnet for enemy attacks, meant to lure reaction forces into an ambush or to divert the allies from operations elsewhere. Ben Het in Kontum Province was besieged from March to July of 1969. Other bases-Thien Phuoc and Thuong Duc in I Corps; Bu Prang, Dak Seang, and Dak Pek in II Corps; and Katum, Bu Dop, and Tong Le Chon in III Corps-were attacked because of their proximity to Communist strongholds and infiltration routes. In some cases camps had to be abandoned, but in most the attackers were repulsed. By the time the 5th Special Forces Group left South Vietnam in March 1971, all CIDG units had been converted to Regional Forces or absorbed by the South Vietnamese Rangers, The departure of the Green Berets brought an end to any significant Army role in the highlands.

Following the withdrawal of the 4th and 9th Divisions, Army units concentrated around Saigon and in the northern provinces. Operating in Quang Ngai, Quang Tin, and Quang Nam Provinces, the 23d Infantry Division (Americal) conducted a series of operations in 1968 and 1969 to secure and pacify the heavily populated coastal plain or southern I Corps, Along the demilitarized zone, the 1st Brigade, 5th Infantry Division (Mechanized), helped marines and South Vietnamese forces to screen the zone and to secure the northern coastal region, including a stretch of highway, the "street without joy," that was notorious from the time of the French. The 101st Airborne Division (converted to the Army's second airmobile division in 1968) divided its attention between the defense of Hue and forays into the enemy's base in the A Shau valley.

Since the 1968 Tet offensive, the Communists had restocked the A Shau valley with ammunition, rice, and equipment. The logistical build-up pointed to a possible NVA offensive in early 1969. In quick succession, Army operations were launched in the familiar pattern: air assaults, establishment of fire support bases, and exploration of the lowlands and surrounding hills to locate enemy forces and supplies. This time the Army met stiff enemy resistance, especially from antiaircraft guns. The North Vietnamese had expected the American forces and now planned to hold their ground.

On 11 May 1969, a battalion of the 101st Airborne Division climbing Hill 937 found the 29th North Vietnamese Regiment waiting for it. The struggle for "Hamburger Hill" raged for ten days and became one of the war's fiercest and most controversial battles. Entrenched in tiers of fortified bunkers with well- prepared fields of fire, the enemy forces withstood repeated attempts to dislodge them. Supported by intense artillery and
air strikes, Americans made a slow, tortuous climb, fighting hand to hand. By the time Hill 937 was taken, three Army battalions and an ARVN regiment had been committed to the battle. Victory, however, was ambiguous as well as costly; the hill itself had no strategic or tactical importance and was abandoned soon after its capture. Critics charged that the battle wasted American lives and exemplified the irrelevance of U.S. tactics in Vietnam. Defending the operation, the commander of the 101st acknowledged that the hill's only significance was that the enemy occupied it. "My mission" he said, "was to destroy enemy forces and installations. We found the enemy on Hill 937, and that is where we fought them."

About one month later the 101st left the A Shau valley, and the North Vietnamese were free to use it again. American plans to return in the summer of 1970 came to nothing when enemy pressure forced the abandonment of two fire support bases needed for operations there. The loss of Fire Support Base O'REILLY, only eleven miles from Hue, was an ominous sign that enemy forces had reoccupied the A Shau and were seeking to dominate the valleys leading to the coastal plain. Until it redeployed in 1971, the 101st Airborne, with the marines and South Vietnamese forces, now devoted most of its efforts to protecting Hue. The operations against the A Shau had achieved no more than Westmoreland's large search and destroy operations in 1967. As soon as the allies left, the enemy reclaimed his traditional bases.

The futility of such operations was mirrored in events on the coastal plain. Here the 23d Infantry Division fought in an area where the population had long been sympathetic to the Viet Cong. As in other areas, pacification in southern I Corps seemed to improve after the 1968 Tet offensive, though enemy units still dominated the piedmont and continued to challenge American and South Vietnamese forces on the coast.  Operations against them proved to be slow, frustrating exercises in warding off NVA and Viet Cong main force units while enduring harassment from local guerrillas and the hostile population. Except during spasms of intense combat, as in the summer of 1969 when the Americal Division confronted the 1st North Vietnamese Regiment, most U.S. casualties were caused by snipers, mines, and booby traps. Villages populated by old men, women, and children were as dangerous as the elusive enemy main force units. Operating in such conditions day after day induced a climate of fear and hate among the Americans. The already thin line between civilian and combatant was easily blurred and violated. In the hamlet of My Lai, elements of the Americal Division killed about two hundred civilians in the spring of 1968. Although only one member of the division was tried and found guilty of war crimes, the repercussions of the atrocity were felt throughout the Army. However rare, such acts undid the benefit of countless hours of civic action by Army units and individual soldiers and raised unsettling questions about the conduct of the war.

What happened at My Lai could have occurred in any Army unit in Vietnam in the late 1960's and early 1970's. War crimes were born of a sense of frustration that also contributed to a host of morale and discipline problems, among enlisted men and officers alike. As American forces were withdrawn by a government eager to escape the war, the lack of a clear military objective contributed to a weakened sense of mission and a
slackening of discipline. The short-timer syndrome, the reluctance to take risks in combat toward the end of a soldier's one-year tour, was compounded by the "last-casualty" syndrome. Knowing that all U.S. troops would soon leave Vietnam, no soldier wanted to be the last to die. Meanwhile, in the United States harsh criticism of the war, the military, and traditional military values had become widespread. Heightened individualism, growing permissiveness, and a weakening of traditional bonds of authority pervaded American society and affected the Army's rank and file. The Army grappled with problems of drug abuse, racial tensions, weakened discipline, and lapses of leadership. While outright refusals to fight were few in number, incidents of "fragging" murderous attacks on officers and noncoms-occurred frequently enough to compel commands to institute a host of new security measures within their cantonments. All these problems were symptoms of larger social and political forces and underlined a growing disenchantment with the war among soldiers in the field.

As the Army prepared to leave Vietnam, lassitude and war- weariness at times resulted in tragedy, as at Fire Support Base MARY ANN in 1971. There soldiers of the Americal Division, soon to go home, relaxed their security and were overrun by a North Vietnamese force. Such incidents reflected a decline in the quality of leadership among both noncommissioned and  commissioned officers. Lowered standards, abbreviated training,
and  accelerated promotions to meet the high demand for noncommissioned and junior officers often resulted in the assignment of squad, platoon, and company  leaders with less combat experience than the troops they led. Careerism and ticket-punching in officer assignments, false reporting and inflated body counts, and revelations of scandal and corruption all raised disquieting questions about the professional ethics of Army leadership. Critics indicted the tactics and techniques used by the Army in Vietnam, noting that airmobility, for example, tended to distance troops from the population they were sent to protect and that commanders aloft in their command and control helicopters were at a psychological and physical distance from the soldiers they were supposed to lead.

Cross-border Operations

With most U.S. combat units slated to leave South Vietnam during 1970 and 1971, time was a critical factor for the success of Vietnamization and pacification. Neither program could thrive if Saigon's forces were distracted by enemy offensives launched from bases in Laos or Cambodia. While Abrams' logistical offensive temporarily reduced the level of enemy activity in the South, bases outside South Vietnam had been inviolable to allied ground forces. Harboring enemy forces, command facilities, and logistical depots, the Cambodian and Laotian bases threatened the fragile progress made in the South since Tet 1968. To the Nixon administration, Abrams' plans to violate the Communist sanctuaries had the special appeal of gaining more time for Vietnamization and of compensating for the bombing halt over North Vietnam.

Because of their proximity to Saigon, the bases in Cambodia received first priority. Planning for the cross border attack occurred at a critical time in Cambodia. In early 1970 Cambodia's-neutralist leader, Prince Norodom Sihanouk, was overthrown by his pro-Western Defense Minister, General Lon Nol. Among Lon Nol's first actions was closing the port of Sihanoukville to supplies destined for Communist forces in the border bases and in South Vietnam. He also demanded that Communist forces leave Cambodia and accepted Saigon's offer to apply pressure against those located near the border. A few weeks earlier, American B-52 bombers had begun in secret to bomb enemy bases in Cambodia. By late April, South Vietnamese military units, accompanied by American advisers, had mounted large-scale ground operations across the border.

On 1 May 1970, units of the 1st Cavalry Division, the 25th Infantry Division, and the 11th Armored Cavalry followed. Cambodia became a new battlefield of the Vietnam War. Cutting a broad swath through the enemy's Cambodian bases, Army units discovered large, sprawling, well-stocked  storage sites, training camps, and hospitals, all recently occupied. What Americans did not find were large enemy forces or COSVN headquarters. Only small delaying forces offered sporadic resistance, while main force units retreated to northeastern Cambodia. Meanwhile the expansion of the war produced violent demonstrations in the United States. In response to the public outcry, Nixon imposed a geographical and time limit on operations in Cambodia, enabling the enemy to stay beyond reach. At the end of June, one day short of the sixty days allotted to the operation, all advisers  accompanying the South Vietnamese and all U.S. Army units had left Cambodia.

Political and military events in Cambodia triggered changes in the war as profound as those engendered by the Tet offensive. From a quiescent "side-show" of the war, Cambodia became an arena for the major belligerents. Military activity increased in northern Cambodia and southern Laos as Hanoi established new infiltration routes and bases to replace those lost during the incursion. Hanoi made clear that it regarded all Indochina  as a single theater of operations. Cambodia itself was engulfed in a virulent civil war.

As U.S. Army units withdrew, the South Vietnamese Army found itself in a race against Communist forces to secure the Cambodian capital of Phnom Penh. Americans provided Saigon's overextended forces air and logistical support to enable them to stabilize the situation there. The time to strengthen Vietnamization gained by the incursion now had to be weighed in the balance against ARVN's new commitment in Cambodia. To the extent that South Vietnam's forces bolstered Lon Nol's regime, they were unable to contribute to pacification and rural security in their own country. Moreover, the South Vietnamese performance in Cambodia was mixed. When working closely with American advisers, the army acquitted itself well. But when forced to rely on its own resources, the army revealed its inexperience and limitations in attempting to plan and execute large operations.

Despite ARVN's equivocal performance, less than a year later the Americans pressed the South Vietnamese to launch a second cross- border operation, this time into Laos. Although U.S. air, artillery, and logistical support would be provided, this time Army advisers would not accompany South Vietnamese forces. The Americans' enthusiasm for the operation exceeded that of their allies. Anticipating high casualties, South Vietnam's leaders were reluctant to involve their army once more in extended operations outside their country. But American intelligence had detected a North Vietnamese build-up in the vicinity of Tchepone, a logistical center on the Ho Chi Minh Trail approximately 25 miles west of the South Vietnamese border in Laos. The Military Assistance Command regarded the build-up as a prelude to an NVA spring offensive in the northern provinces. Like the Cambodian incursion, the Laotian invasion was justified as benefiting Vietnamization, but with the added bonuses of spoiling a prospective offensive and cutting the Ho Chi Minh Trail.

In preparation for the operation, Army helicopters and artillery were moved to the vicinity of the abandoned base at Khe Sanh. The 101st Airborne Division conducted a feint toward the A Shau valley to conceal the true objective. On 8 February 1971, spearheaded by tanks and with airmobile units leapfrogging ahead to establish fire support bases in Laos, a South Vietnamese mechanized column advanced down Highway 9 toward Tchepone. Operation LAM SON 719 had begun.

The North Vietnamese were not deceived. South Vietnamese forces numbering about 25,000 became bogged down by heavy enemy resistance and bad weather. The drive toward Tchepone stalled. Facing the South Vietnamese were elements of five NVA divisions, as well as a tank regiment, an artillery regiment, and at least nineteen antiaircraft battalions. After a delay of several days, South Vietnamese forces air-assaulted into the  heavily bombed town of Tchepone. By that time, the North Vietnamese had counterattacked with Soviet-built T54 and T55 tanks, heavy artillery, and infantry. They struck the rear of the South Vietnamese forces strung out on Highway 9, blocking their main avenue of withdrawal. Enemy forces also overwhelmed several South Vietnamese fire support bases, depriving ARVN units of desperately needed flank protection. The South Vietnamese also lacked antitank weapons to counter the North Vietnamese armor that appeared on the Laotian jungle trails. The result was near- disaster. Army helicopter pilots trying to rescue South Vietnamese soldiers from their besieged hilltop fire bases encountered intense antiaircraft fire. Panic ensued when some South Vietnamese units ran out of ammunition. In some units, all semblance of an orderly withdrawal vanished as desperate South Vietnamese soldiers pushed the wounded off evacuation helicopters or clung to helicopter skids to reach safety. Eventually, ARVN forces punched their way out of Laos, but only after paying a heavy price.

That the South Vietnamese Army had reached its objective of Tchepone was of little consequence. Its stay there was brief and the supply caches it discovered disappointingly small. Saigon's forces had failed to sever the Ho Chi Minh Trail; infiltration reportedly increased during LAM SON 719, as the North Vietnamese shifted traffic to roads and trails further to the west in Laos. In addition to losing nearly 2,000 men, the South Vietnamese lost large amounts of equipment during their disorderly withdrawal, and the U.S. Army lost 107 helicopters, the highest number in any one operation of the war. Supporters pointed to heavy enemy casualties and argued that equipment losses were reasonable, given the large number of helicopters used to support LAM SON 719. The battle nevertheless raised disturbing questions among Army officials about the vulnerability of helicopters in mid- or high intensity conflict. What was the future of airmobility in any war where the enemy possessed a significant antiaircraft capability?

LAM SON 719 proved to be a less ambiguous test of Vietnamization than the Cambodian incursion. The South Vietnamese Army did not perform well in Laos. Reflecting on the operation, General Ngo Quan Truong the commander of I Corps, noted ARVN's chronic weakness in planning for and coordinating combat support. He also noted that from the battalion to the division level, the army had become dependent on U.S. advisers. At the highest levels of command, he added, "the need for advisers was more acutely felt in two specific areas: planning and leadership. The basic weakness of ARVN units at regimental and sometimes division level in those areas," he continued, "seriously affected the performance of subordinate units." LAM SON 719 scored one success, forestalling a Communist spring offensive in the northern provinces; in other respects, it was a failure and an ill omen for the future.

Withdrawal: The Final Battles

As the Americans withdrew, South Vietnam's combat capability declined. The United States furnished its allies the heavier M48 tank to match the NVA's T54 tank and heavier artillery to counter North Vietnamese 130-mm. guns, though past experience suggested that additional arms and equipment could not compensate for poor skills and mediocre leadership. In fact, the weapons and equipment were insufficient to offset the reduction in U.S. combat strength. In mid-1969, for example, an aggregate of fifty-six allied combat battalions were present in South Vietnam's two northern provinces; in 1972, after the departure of most American units, only thirty battalions were in the same area. Artillery strength in the northern region declined from approximately 400 guns to 169 in the same period, and ammunition supply rates fell off as well. Similar reductions took place throughout South Vietnam, causing decreases in mobility, firepower, intelligence support, and air support. Five thousand American helicopters were replaced by about 500. American specialties -B-52 strikes, photo reconnaissance, and the use of sensors and other means of target acquisition-were drastically curtailed.

Such losses were all the more serious because operations in Cambodia and Laos had illustrated how deeply ingrained in the South Vietnamese Army the American style of warfare had become. Nearly two decades of U.S. military involvement were exacting an unexpected price. As one ARVN division commander commented, "Trained as they were through combined action with US units, the [South Vietnamese] unit commander was used to the employment of massive firepower." That habit, he added, "was hard to relinquish."

By November 1971, when the 101st Airborne Division withdrew from the South, Hanoi was planning its 1972 spring offensive. With ARVN's combat capacity diminished and nearly all U.S. combat troops gone, North Vietnam sensed an opportunity to demonstrate the failure of Vietnamization, hasten ARVN's collapse, and revive the stalled peace talks. In its broad outlines and goals, the 1972 offensive resembled Tet 1968, except that the North Vietnamese Army, instead of the Viet Cong, bore the major burden of combat. The Nguyen-Hue offensive or Easter offensive began on 30 March 1972. Total U.S. military strength in South Vietnam was about 95,000, of which only 6,000 were combat troops, and the task of countering the offensive on the ground fell almost exclusively to the South Vietnamese. Attacking on three fronts, the North Vietnamese Army poured across the demilitarized zone and out of Laos to capture Quang Tri, South Vietnam's northernmost province. In the Central Highlands, enemy units moved into Kontum Province, forcing Saigon to relinquish several border posts before government forces contained the offensive. On 2 April, Viet Cong and North Vietnamese forces struck Loc Ninh, just south of the Cambodian border on Highway 13, and advanced south to An Loc along one of the main invasion routes toward Saigon. A two-month-long battle ensued, until enemy units were driven from An Loc and forced to disperse to bases in Cambodia. By late summer the Easter offensive had run its course; the South Vietnamese, in a slow, cautious counteroffensive, recaptured Quang Tri City and most of the lost province. But the margin of victory or defeat often was supplied by the massive supporting firepower provided by U.S. air and naval forces.

The tactics of the war were changing. Communist forces now made extensive use of armor and artillery. Among the new weapons in the enemy's arsenal was the Soviet SA-7 hand-held antiaircraft missile, which posed a threat to slow-flying tactical aircraft and helicopters. On the other hand, the Army's attack helicopter, the Cobra, outfitted with TOW antitank missiles, proved effective against NVA armor at stand-off range. In their antitank role, Army attack helicopters were crucial to ARVN's success at An Loc, suggesting a larger role for helicopters in the future as part of a combined arms team in conventional combat.

Vietnamization continued to show mixed results. The benefits of the South Vietnamese Army's newly acquired mobility and firepower were dissipated as it became responsible for securing areas vacated by American forces. Improvements of territorial and paramilitary troops were offset as they became increasingly vulnerable to attack by superior North Vietnamese forces. Insurgency was also reviving. Though their progress was less spectacular than the blitzkrieg-like invasion of the South, North Vietnamese forces entered the Delta in thousands between 1969 and 1973 to replace the Viet Cong-one estimate suggested a tenfold increase in NVA strength, from 3,000 to 30,000, in this period. Here the fighting resembled that of the early 1960's, as enemy forces attacked lightly defended outposts and hamlets to regain control over the rural population in anticipation of a cease-fire. The strength of the People's Self-Defense Force, Saigon's first line of hamlet and village defense, after steady increases in 1969 and 1970, began to decline after 1971, also suggesting a revival of the insurgency in the countryside. Pursuing a strategy used successfully in the past, the North Vietnamese forced ARVN troops to the borders, exposing the countryside and leaving its protection in the hands of weaker forces.

Such unfavorable signs, however, did not disturb South Vietnam's leaders as long as they could count on continued United States air and naval support. Nixon's resumption of the bombing of North Vietnam during the Easter offensive and, for the first time, his mining of North Vietnamese ports encouraged this expectation, as did the intense American bombing of Hanoi and Haiphong in late 1972. But such pressure was intended, at least in part, to force North Vietnam to sign an armistice. If Thieu was encouraged by the display of U.S. military muscle, the course of negotiations could only have been a source of discouragement. Hanoi dropped an earlier demand for Thieu's removal, but the United States gave up its insistence on Hanoi's withdrawal of its troops from the South. In early 1973 the United States, North and South Vietnam, and the Viet Cong signed an armistice that promised a cease-fire and national reconciliation. In fact, fighting continued, but the  Military Assistance Command was dissolved, remaining U.S. forces withdrawn, and American military action in South Vietnam terminated. Perhaps most important of all, American advisers- still in many respects the backbone of ARVN's command structure- were withdrawn.

Between 1973 and 1975 South Vietnam's military security further declined through a combination of old and new factors. Plagued by poor maintenance and shortages of spare parts, much of the equipment provided Saigon's forces under Vietnamization became inoperable. A rise in fuel prices stemming from a worldwide oil crisis further restricted ARVN's use of vehicles and aircraft. South Vietnamese forces in many areas of the country were on the defensive, confined to protecting key towns and installations. Seeking to preserve its diminishing assets, the South Vietnamese Army became garrison bound and either reluctant or unable to react to a growing number of guerrilla attacks that eroded rural security. Congressionally mandated reductions in U.S. aid further reduced the delivery of repair parts, fuel, and ammunition. American military activities in Cambodia and Laos, which had continued after the cease-fire in South Vietnam went into effect, ended in 1973 when Congress cut off funds. Complaining of this austerity, President Thieu noted that he had to fight a "poor man's war." Vietnamization's legacy was that South Vietnam had to do more with less.

In 1975 North Vietnam's leaders began planning for a new offensive, still uncertain whether the United States would resume bombing or once again intervene in the South. When their forces overran Phuoc Long Province, north of Saigon, without any American military reaction, they decided to proceed with a major offensive in the Central Highlands. Neither President Nixon, weakened by the Watergate scandal and forced to resign, nor his successor, Gerald Ford, was prepared to challenge Congress by resuming U.S. military activity in Southeast Asia. The will of Congress seemed to reflect the mood of an American public weary of the long and inconclusive war.

What had started as a limited offensive in the highlands to draw off forces from populated areas now became an all-out effort to conquer South Vietnam. Thieu, desiring to husband his military assets, decided to retreat rather than to reinforce the highlands. The result was panic among his troops and a mass exodus toward the coast. As Hanoi's forces spilled out of the highlands, they cut off South Vietnamese defenders in the northern provinces from the rest of the country. Other NVA units now crossed the demilitarized zone, quickly overrunning Hue and Da Nang, and signaling the collapse of South Vietnamese resistance in the north. Hurriedly established defense lines around Saigon could not hold back the inexorable enemy offensive against the capital. As South Vietnamese leaders waited in vain for American assistance, Saigon fell to the  Communists on 29 April 1975.

The Post-Vietnam Army

Saigon's fall was a bitter end to the long American effort to sustain South Vietnam. Ranging from advice and support to direct participation in combat and involving nearly three million U.S. servicemen, the effort failed to stop Communist leaders from reaching their goal of unifying a divided nation. South Vietnam's military defeat tended to obscure the crucial inability of this massive military enterprise to compensate for Saigon's political shortcomings. Over a span of nearly two decades, a series of regimes failed to mobilize fully and effectively their nation's political, social, and economic resources to foster a popular base of support. North Vietnamese main force units ended the war, but local insurgency among the people of the South made that outcome possible and perhaps inevitable.

The U.S. Army paid a high price for its long involvement in South Vietnam. American military deaths exceeded 58,000, and of these about two thirds were soldiers. The majority of the dead were low-ranking enlisted men (E-2 and E-3), young men twenty- three years old or younger, of whom approximately 13 percent were black. Most deaths were caused by small-arms fire and gunshot, but a significant portion, almost 30 percent, stemmed from mines, booby traps, and grenades. Artillery, rockets, and bombs accounted for only a small portion of the total fatalities.

If not for the unprecedented medical care that the Army provided in South Vietnam, the death toll would have been higher yet. Nearly 300,000 Americans were wounded, of whom half required hospitalization. The lives of many seriously injured men, who would have become fatalities in earlier wars, were saved by rapid helicopter evacuation direct to hospitals close to the combat zone. Here, relatively secure from air and ground attack, usually unencumbered by mass casualties, and with access to an uninterrupted supply of whole blood, Army doctors and nurses availed themselves of the latest medical technology to save thousands of lives. As one medical officer pointed out, the Army was able to adopt a "civilian philosophy of casualty triage" in the combat zone that directed the "major effort first to the most seriously injured." But some who served in South Vietnam suffered more insidious damage from the adverse psychological effects of combat or the long-term effects of exposure to chemical agents. More than a decade after the end of the war, 1,761 American soldiers remain listed as missing in action.

The war-ravaged Vietnamese, north and south, incurred the greatest losses. South Vietnamese military deaths exceeded 200,000. War-related civilian deaths in the South approached a half-million, while the injured and maimed numbered many more. Accurate estimates of enemy casualties run afoul of the difficulty in distinguishing between civilians and combatants, imprecise body counts, and the difficulty of verifying casualties in areas controlled by the enemy. Nevertheless, nearly a million Viet Cong and North Vietnamese soldiers are believed to have perished in combat through the spring of 1975.

For the U.S. Army the scars of the war ran even deeper than the grim statistics showed. Given its long association with South Vietnam's fortunes, the Army could not escape being tarnished by its ally's fall. The loss compounded already unsettling questions about the Army's role in Southeast Asia, about the soundness of its advice to the South Vietnamese, about its understanding of the nature of the war, about the appropriateness of its strategy and tactics, and about the adequacy of the counsel provided by Army leaders to national decision makers. Marked by ambiguous military objectives, defensive strategy, lack of tactical initiative, ponderous tactics, and untidy command arrangements, the struggle in Vietnam seemed to violate most of the time-honored principles of war. Many officers sought to erase Vietnam from the Army's corporate memory, feeling uncomfortable with the ignominy of failure or believing that the lessons and experience of the war were of little use to the post-Vietnam Army. Although a generation of officers, including many of the Army's future leaders, cut their combat teeth in Vietnam, many regretted that the Army's reputation, integrity, and professionalism had been tainted in the service of a flawed strategy and a dubious ally.

Even before South Vietnam fell, Army strategists turned their attention to what seemed to them to be the Army's more enduring and central mission-the defense of western Europe. Ending a decade of neglect of its forces there, the Army began to strengthen and modernize its NATO contingent. Army planners doubted that in any future European war they would enjoy the luxury of a gradual, sustained mobilization, or unchallenged
control of air and sea lines of communication, or access to support facilities close to the battlefield. France's decision in 1966 to end its affiliation with NATO had already forced the Army to re-evaluate its strategy and support arrangements. The end of the draft in 1972 and the transition to an all-volunteer Army in 1973-a reflection of popular dissatisfaction with the Vietnam War-added to the unlikelihood of another war similar to Vietnam and made it seem more than ever an anomaly.

Instead, Army planners faced a possible future conflict that would begin with little or no warning and confront allied forces-in-being with a numerically superior foe. Combat in such a war was likely to be violent and sustained, entailing deep thrusts by armored forces, intense artillery and counterbattery fire, and a fluid battlefield with a high degree of mobility. Army doctrine to fight this war, codified in 1976 in  FM (Field Manual) 100-5, Operations, barely acknowledged the decade of Army combat in Vietnam. The new doctrine of "active defense" drew heavily on the experience of armored operations in World War II and recent fighting in the Middle East between Arab and Israeli forces. From a study of about 1,000 armored battles, Army planners deduced that an outnumbered defender could force a superior enemy to concentrate his forces and reveal his intentions, and thus bring to bear in the all-important initial phase of the battle sufficient forces and firepower in the critical area to defeat his main attack. The conversion of the 1st Cavalry Division, the unit that exemplified combat operations in South Vietnam, from an airmobile division to a new triple capabilities (TRICAP) division symbolized the post- Vietnam Army's reorientation toward combat in Europe. Infused with additional mechanized and artillery forces to give it greater flexibility and firepower, the division's triple capabilities-armor, airmobility, and air cavalry-better suited it to carry out the tactical concepts of FM 100-5 than its previous configuration.

Yet the Army did not totally ignore its Vietnam experience. U. S. armor and artillery forces had gained valuable experience there in coordinating operations with airmobile forces. Although some in the military questioned whether helicopters could operate in mid-intensity conflict Army doctrine rested heavily on concepts of airmobility that had evolved during Vietnam. Helicopters were still expected to move forces from one sector of the battlefield to another, to carry out reconnaissance and surveillance, to provide aerial fire support, and to serve as antitank weapons systems In many respects, the role contemplated for helicopters in the post-Vietnam Army harkened back to concepts of airmobility originally formulated for the atomic battlefield of the early 1960's, but modified by combat in Vietnam. Like the Army of the Vietnam era, the postwar Army continued a common hallmark of the American military tradition by emphasizing technology and firepower over manpower.

The Army's new operational doctrine had its share of critics. Stressing tactical operations of units below the division, the doctrine of FM 100-5 neglected the role of larger Army echelons. Recognition of this deficiency led to a revival of interest in the role of divisions, corps, and armies in the gray area between grand strategy and tactics. But some strategists warned that the Army seemed to be preparing for the war it was least likely to fight. Like the strategists of the New Look in the 1950's, they viewed an attack on Army forces in Europe as a mere trip wire that would ignite a nuclear confrontation between the superpowers and thus make the land battle irrelevant. With insurgencies, small wars, subversion, and terrorism flourishing throughout Asia, Africa, and Latin America, others believed that Army would sooner or later find itself once again engaged in conflicts that closely resembled Vietnam.

Ten years after the loss of South Vietnam, the U.S. Army's major overseas commitments remained anchored in NATO and South Korea. International realities still compelled it to prepare for a variety of contingencies. In addition to organizing divisions to fight in Europe, the Army revived its old interest in light infantry divisions. By the mid-1980's two such divisions, the 10th Mountain Division and the 6th Infantry Division  (Light), had been activated, giving the Army once again a total of eighteen divisions. Lower active-duty strength required many divisions to be fleshed out by Reserve Components before they could be committed to combat. Nevertheless, the Army viewed its new divisions as suitable for use in a rapid deployment force to reinforce NATO or world trouble spots. Although their strength was drastically reduced following the Vietnam War, Special Forces continued to be called upon to advise and train anti- Communist military forces in Latin America and elsewhere and to participate in a variety of special activities to counter terrorism. Operations like the abortive attempt to rescue American hostages in Iran and the successful operation to prevent a Communist takeover of the Caribbean island of Grenada attested to the Army's continuing need for both rapidly deployable and special-purpose forces. The realities of a complex world reinforced the pervasive influence of flexible response on the U.S. national security policy. Many other missions fell under the doctrinal umbrella of low-intensity conflict, a vague and faddish term that became popular in the 1980's as counterinsurgency had two decades earlier. The relevance of Vietnam to low-intensity conflict remains an open question.

Nevertheless, by the 1980's the conduct and lessons of the war in Vietnam had again become the subject of lively debate in the Army. Reassessments of its role tend to center around the issue of whether the Army should have devoted more effort to pacification or to defeating the conventional military threat posed by North Vietnam. These issues stem from the ambiguities of the war and the paradox of the Army's experience. Reliance on massive firepower and technological superiority and the ability to marshal vast logistical resources have been hallmarks of the American military tradition. Tactics have often seemed to exist apart from larger issues, strategies, and objectives. Yet in Vietnam the Army experienced tactical success and strategic failure. The rediscovery of the Vietnam War suggests that its most important legacy may be the lesson that unique historical, political, cultural, and social factors always impinge on the military. Strategic and tactical success rests not only on military progress but on correctly analyzing the nature of the particular conflict, understanding the enemy's strategy, and realistically assessing the strengths and weaknesses of allies. A new humility and a new sophistication may form the best parts of the complex heritage left the Army by the long, bitter war in Vietnam.

Transcribed by:
Larry W.Jewell
jewell@mace.cc.purdue.edu

Print