THE U.S. ARMY IN VIETNAM FROM TET TO THE FINAL WITHDRAWAL, 1968-1975

THE U.S. ARMY IN VIETNAM
FROM TET TO THE FINAL WITHDRAWAL, 1968-1975

 

y the beginning of 1968 the United States had been involved in military operations in Vietnam for over seven years and in major ground combat for two-and-a-half years. In-country U.S. military strength had risen to 485,000, and General William C. Westmoreland had been using his troops aggressively in all parts of South Vietnam to pursue the enemy’s main forces and to help shield the population from enemy attack. U.S. and allied forces had conducted hundreds of operations both large and small, and some forty of that number had each achieved a verified body count of 500 or more enemy soldiers. According to MACV estimates, 81,000 Communist soldiers had been killed in 1967, giving substance to Westmoreland’s belief that the allies were slowing winning the war in Vietnam.
Other trends seemed to confirm his optimism. While the American public appeared to be growing weary of recitations of statistics, the Johnson administration continued to put faith in them as one way to make sense of a war that was so difficult to measure. The pacification trends were especially heartening. By 1967 some two-thirds of the hamlets in South Vietnam were judged secure and under the control of the central government. (In early 1965 the government was being chased from the countryside and on the verge of collapse.) Meanwhile, enemy troop strength in the South had dropped by a quarter to 220,000, the result both of attrition on the battlefield and declines in infiltration from the North and recruitment in the South. In 1965 and 1966 some 9,000 North Vietnamese a month were coming down the Ho Chi Minh Trail to fight in the South, whereas in 1967 the figure was 6,000 a month. (See Chart 1 for yearly infiltration rates.) Viet Cong recruitment in the villages had fallen to half its previous monthly average of 7,000. All this gave precious breathing space to the South Vietnamese as they

*Figures are estimates only, averaging the PAVN-stated total of 165,000 for 1970 and 1971 combined.

335

336

Map 17

Aftermath of Heavy Fighting in Downtown Saigon

sively at My Tho, Cai Lay, and Vinh Long and by the second week of February had crippled the offensive in the upper Mekong Delta. In the western highlands town of Pleiku, American tankers, cavalrymen, artillerymen, and engineers joined South Vietnamese cavalry and infantry
to hold off Viet Cong assaults for nearly a week. The situation was particularly grave in northern I Corps. There, the Viet Cong and North Vietnamese struck at roads, waterways, and bridges and threatened to sever the allies’ logistical lifeline. Writing on February 9 to the Chairman of the Joint Chiefs of Staff, General Earle G. Wheeler, Westmoreland observed that logistics would be the key to winning the fight in the northern provinces. Tactical airlift for a time was the major source of supplies for the 1st Cavalry Division just moved to I Corps. While the fight for Quang Tri City was essentially over after two days, the critical stretch of Highway 1 from Da Nang northward to Phu Bai and Hue had to wait until marines, paratroopers, and their engineers linked up in the flatlands to the north of the Hai Van Pass. Although the highway finally became passable to U.S. convoys on March 1, the flow of supplies remained unsatisfactory for several weeks, necessitating the opening just east of Quang Tri City of a large shore operation at Wunder Beach (Than My Thuy). Marines, Navy Seabees, and Army lighterage and port units, chiefly the 159th Transportation Battalion, were all involved.
The most tenacious combat occurred in Hue, the ancient capital of Vietnam. There, the 1st Cavalry and 101st Airborne Divisions, together with marines and South Vietnamese forces, including the South Vietnamese 1st Infantry Division, 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; North Vietnamese strategists thought that here if anywhere the general offensive/
general uprising might gain a political foothold. Hence they threw

most of seven North Vietnamese regiments into the battle, bringing several units down from Khe Sanh, an indication 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 more than three weeks to recapture the city and could not shut down the enemy’s supply conduit into Hue until February 24.
Throughout the country, the South Vietnamese forces acquitted themselves well, despite high casualties and many desertions. Stunned by the attacks, civilian support for the government of President Nguyen Van Thieu coalesced instead of weakening. Many Vietnamese for whom the war had been a mere annoyance were outraged, not the least by confirmation that the Communists had executed almost 3,000 civilians at Hue. Capitalizing on the new feeling, South Vietnam’s leaders for the first time enacted a 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 grounds of the American Embassy in the heart of Saigon and of 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

339

and enemy forces again infiltrated into Saigon, leading to heavy destruction in several neighborhoods. But these were the last gasps of the general offensive/general uprising. Thereafter the Viet Cong and North Vietnamese generally dispersed and avoided contact with Americans. In turn the allies withdrew from Khe Sanh 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, having suf-

340

fered heavy losses, 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 1950s. 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 the South Vietnamese Army’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 Abrams had the aura of a blunt, hard-talking, World War II tank commander, he had spent a year 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 North Vietnamese, both guerrilla and regular Communist forces had adopted a defensive posture. Nevertheless, 90,000 North Vietnamese Army troops were in the South or in border sanctuaries waiting to resume the offensive at a propitious time.

 

341

the enemy’s base of support among the rural population.
To the greatest extent possible, Abrams planned to improve the South Vietnamese Army’s performance by enhancing training and 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 toward the border and to assume a role similar to that of U.S. forces between 1965 and 1969. The Regional and Popular Forces in turn were to take over the South Vietnamese Army’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 cooperation between American and South Vietnamese forces, and the importance of coordinating all echelons of Saigon’s armed forces, Abrams spoke of a “one war” concept.
Yet even in his emphasis on combined operations, his targeting of enemy base areas, and American support of pacification, Abrams’ strategy had strong elements of continuity with Westmoreland’s. For the first and second, operations in War Zones C and D and in the Binh Dinh piedmont in 1966 and 1967 were ample precedents. Westmoreland had also laid the foundation for a more extensive U.S. role in pacification in 1967 by establishing Civil Operations and Rural (later changed to Revolutionary) 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 importance. During 1967, for example, there were 108 American advisers attached to the Regional Forces and Popular

342

343

officials abused the program, using it as a vehicle for personal vendettas. In some cases, district PHOENIX officials accepted bribes from the Viet Cong for the release of certain suspects. Some districts released as many as 60 percent
of the suspected members of the enemy underground.
Even land reform, the South Vietnamese government’s most successful program for building political
strength in the countryside, rested on an uncertain foundation. Enacted in 1970, the land-to-the-tiller program was one of the most advanced undertaken anywhere in the developing world. President Thieu gave it unwavering support and placed strong leaders in charge. Land tenancy dropped from 60 to 10 percent between 1970 and 1973. Computers sped up the pro-

344

cess of registering ownership and issuing land titles, bypassing the sclerotic
South Vietnamese bureaucracy. Even so, the social and economic benefits for the peasantry were understood to be only as durable as American aid and the conventional-force security shield. In that sense, despite the progress made, the entire South Vietnamese enterprise remained in doubt.
Influencing all parts of this struggle to hold the South was a new defense policy enunciated by Richard M. Nixon, who became President in January 1969. The Nixon Doctrine hearkened 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

       The U.S. troop withdrawals began in the summer of 1969, when two brigades of the 9th Infantry Division pulled out of III and IV Corps and a regiment of the 3d Marine Division departed from northern I Corps. These units were selected because they were considered first-rate and would consequently make the reduction in forces credible to all concerned—not just to the governments in Hanoi and Saigon but also to the American public. The 9th Division was chosen, according to General Abrams, because the war south of Saigon had been a South Vietnamese affair for years and was apparently going well. The marines would be leaving their area of operations to the best South Vietnamese division, the 1st Infantry Division, and to the remainder of their parent Marine unit, now reinforced along the demilitarized zone by the heavy brigade of the U.S. Army’s 5th Division. The northernmost provinces, by all accounts, were thus also secure. The one area of the country where Abrams refused to thin out his forces was the territory north and west of Saigon, the arc protecting the capital. Saigon was the ultimate war prize, and everything depended on its security, from holding fast to public support in the United States and building a negotiating advantage to giving the South Vietnamese time to grow strong in their own defense. Abrams was not prepared to gamble Saigon’s security on a military experiment, at least not yet.
Consequently, when a new threat emerged in III Corps—seven North Vietnamese regiments, including the entire 1st People’s Army of Vietnam (PAVN) Division, arrived from the highlands to reinforce the Central Office for South Vietnam (COSVN)—Abrams went on the offensive. Starting in late 1968 and for the next year and a half, U.S. forces, including the 1st Cavalry Division operating in III Corps for the first time in the war, engaged in a corps-wide counterattack to locate and destroy enemy units. The Americans combined large- and small-unit operations, frequent sweeps through enemy bases, and persistent screening of the Cambodian border to prevent the main forces from

returning. Commanded by Maj. Gens. George I. Forsythe and Elvy B. Roberts, the 1st Cavalry Division waged the border battle. Straddling the enemy’s jungle trails through Tay Ninh, Binh Long, and Phuoc Long Provinces and making full use of its helicopter mobility, it fought the enemy’s units as they crossed from Cambodia.
The link between the division’s mobility and its ability to carry on the fight as light infantry was the firebase. Although the firebase had evolved over the course of the war into a familiar component of American operations, the 1st Cavalry Division raised its use to a tactical art. Most Army firebases in South Vietnam contained an artillery battery or two and the command post of an infantry battalion and were built for temporary occupation. The 1st Cavalry Division’s firebases tended to be smaller and more fleeting still. In its first month in III Corps, November 1968, the division built a line of fifteen bases right up to the border. When Firebase DOT, one of four bases west of Quan Loi, was nearly overrun, commanders established a new screen across the middle of War Zone C, far enough from Cambodia to give them warning of any attack. Throughout 1969 the division expanded its interdiction both east and west, leapfrogging from firebase to firebase and chewing up enemy troop concentrations as they tried to sideslip south. This made it easier for allied units closer to Saigon to keep the enemy remnants away from the population.
Nearer the capital, the 1st and 25th Infantry Divisions continued the fight in their traditional haunts to the north and west, but in somewhat reduced operating territory since border coverage was no longer required. Intensifying their operations behind the border screen of the airmobile division, they zeroed in on pockets of enemy resistance that still threatened the city. For the 1st Division, few of the battles were dramatic, except for the soldiers who fought them, but were typically small sweeps and night ambushes in the rolling hills along Highway 13, punctuated by clear-and-hold missions with South Vietnamese regu-

Long Range Patrol, James R. Drake, 1969

ilars, Regional Forces, and the police. The more dramatic encounters took place in the tactical arena of the 25th Division. Here lay the Tay Ninh corridor, one of the traditional enemy funnels from the Cambodian sanctuary to the outskirts of Saigon. When the division erected firebase defenses squarely in the enemy’s path, a contest of wills was inevitable. One of those fortresses, near Tay Ninh City, was Firebase CROOK. Small, unprepossessing, and seemingly vulnerable, defended by a battery of light artillery and a company of infantry, CROOK was in fact a formidable redoubt with major tactical advantages: deeply dug with reinforced bunkers, equipped with remote sensors and radar, and well within range of medium and heavy artillery and, like all bases, supported by air power. In June 1969 the 9th People’s Liberation Armed Forces (PLAF) Divisiondetermined to overrun it and spent three days and over 400 dead in the vain attempt (one American soldier died). Further attacks
followed on Tay Ninh City and other bases, all beaten back with heavy enemy casualties. By late 1969 the corridor had quieted; the 25th Division turned to pacification, running scores of medical aid missions and hundreds of joint operations with South Vietnamese forces and gathering in large numbers of defectors from local guerrilla units, probably the best indication available of pacification’s success. Whatever the situation elsewhere in Vietnam, III Corps was the one place where U.S. commanders had enough troops to deal with the threat.
As III Corps stabilized behind the allied shield, an uneasy sense of hope took hold in Saigon. The city was not impregnable. During the Tet celebration in 1969 heavy fighting broke out near Bien Hoa and Long Binh; into the early summer, enemy troops could still penetrate close enough to launch the occasional rocket attack or set off a bomb. Such incidents terrorized civilians, caused military casualties, and raised questions about the central government’s ability to protect its citizens. The rocket attacks were especially troublesome. An economy-of-force measure, they brought little risk to the enemy and compelled allied forces to suspend other operations while they cleared the “rocket belt” around the urban center. By the autumn, however, the attacks had virtually ceased. Saigon seemed to fall back into a period of tranquility and prosperity in which the main concern seemed to be not the fighting off in the distance but a wartime inflation eating into the purchasing power of the urban population. The trauma visited upon the city during Tet 1968 had become a bad memory on the wane.
In the Central Highlands, the war of attrition continued. Until its redeployment in 1970, the 4th Infantry Division protected major highland population centers and kept important interior roads clear. 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—Tien 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

Such incidents terrorized civilians, caused military casualties, and raised questions about the central government’s ability to protect its citizens.

347

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 in the northern provinces as well as around Saigon. 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 of southern I Corps. Along the demilitarized zone, the 1st Brigade, 5th Division, helped marines and South Vietnamese forces to screen the zone and secure the northern coastal region, including the stretch of Highway 1 that the enemy had cut during the 1968 Tet offensive. The 101st Airborne Division (converted to the Army’s second airmobile division in 1969) 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 buildup pointed to a possible North Vietnamese offensive in early 1969. In quick succession, Army operations were launched in the familiar pattern: air assaults, establishment of firebases, and exploration of the lowlands and surrounding hills to locate enemy forces and supplies. As the Army always had in the A Shau Valley, it once again met stiff resistance, especially from antiaircraft guns. The North Vietnamese had expected the American forces and now planned to hold their ground.
On May 11, 1969, a battalion of the 101st Airborne Division climbing
Hill 937 found elements of the 29th PAVN 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 at close quarters. By the time the allies took Hill 937, three U.S. Army battalions and a South Vietnamese battalion from the 1st Division 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 large-unit tactics in Vietnam. Defending the operation, the commander of the 101st, Maj. Gen. Melvin Zais, 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 Airborne Division 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 firebases needed for operations
there. The loss of Firebase 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 redeployed in 1971, the 101st Airborne Division, with the marines and South Vietnamese forces, now devoted most of its efforts to protecting Hue. While the operations in western I Corps had inflicted casualties

on the enemy and bought the allies some time, it remained to be seen whether the South Vietnamese Army could hold the area once American
forces departed.
Operations on the coastal plain brought uncertain outcomes as well. Here, the Americal 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 North Vietnamese 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 1stPAVN Regiment, most U.S. casualties were from 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 hatred 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 March 1968. Although only one member of the division was tried and found guilty of war crimes, the atrocity reverberated 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.
War crimes such as at My Lai 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

 

349

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 Firebase 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 commissioned and noncommissioned 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 the Army used 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 South Vietnam’s
forces were distracted by enemy offensives launched from bases in Cambodia or Laos. While Abrams’ operations temporarily reduced the level of enemy activity in the South, bases outside South Vietnam had been strictly off limits to allied ground forces. This rankled U.S. commanders, who regarded the restriction as a potentially fatal mistake. By harboring enemy forces, command facilities, and logistical depots, the Cambodian and Laotian bases threatened all the progress the allies had made in the South since Tet 1968. To the Nixon administration, Abrams’ desire to attack 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 the proximity of the Cambodian bases to Saigon, they 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. Nol closed 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 the South Vietnamese government’s offer to apply pressure against those located near the border. (A year earlier American

351

and time limits on operations in Cambodia, which enabled 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 the Tet offensive had engendered. From a quiescent sideshow of the war, Cambodia became an arena for the major belligerents. Military activity increased in northern Cambodia and southern Laos as North Vietnam established new infiltration routes and bases to replace those lost during the incursion. North Vietnam made clear that it regarded all Indochina as a single theater of operations. Cambodia itself was engulfed in a 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 South Vietnam’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 the South Vietnamese Army’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; though there were flaws in planning and the use of air and artillery support. The South Vietnamese logistical system, with a few exceptions, proved adequate. The difficulty was that the North Vietnamese Army largely chose not to fight, so the South Vietnamese Army was never really tested. Furthermore, the South Vietnamese command had relied on rangers, armored cavalry, and airborne troops—elite units—bypassing the mediocre infantry divisions hampered by their politics. If the elite units performed credibly, the shortcomings in the regular army remained intact, starting with poor leadership and lack of discipline.
Despite equivocal results in Cambodia, less than a year later the Americans pressed the South Vietnamese to launch a second cross-border operation, this time into Laos. Although the United States would provide air, artillery, and logistical support, 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 buildup in the vicinity of Tchepone, Laos, a logistical center on the Ho Chi Minh Trail approximately twenty-five miles west of the South Vietnamese border. The Military Assistance Command regarded the buildup as a prelude to a North Vietnamese 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 off the Ho Chi Minh Trail. This would be the last chance for the South Vietnamese to cut the Ho Chi Minh Trail while American forces were available to provide support. A decade earlier military analysts had developed plans to use corps-size American and allied forces to block the infiltration routes in

353

sabotage. All operations were limited to a strip along the border extending no more than twenty kilometers into Laos. Later operations expanding into Cambodia were code-named DANIEL BOONE, later SALEM HOUSE. Between 1965 and late 1970, SHINING BRASS/PRAIRIE FIRE/SALEM HOUSE/DANIEL BOONE launched more than 1,600 missions into the enemy base and trail complex, providing a useful supplement to aerial and electronic intelligence but not tying down several North Vietnamese divisions as advocates of the program maintained. SOG was still running operations in Laos when the allies launched their cross-border offensive in 1971.
Planning for the offensive began in great secrecy in January and involved staff from Lt. Gen. James W. Sutherland’s XXIV Corps and Lt. Gen.

354

Hoang Xuan Lam’s I Corps. So tightly held was information on the impending operation that logistical and signal preparations that required long lead time were put in jeopardy and a combined tactical command post was not established until well into the offensive. In preparation for the attack, Army helicopters, artillery, and supplies were moved at the last minute 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 February 8, 1971, spearheaded by M41 tanks and with units from the 1st Infantry, 1st Airborne, and Marine Divisions leapfrogging into Laos to establish firebases on the flanks of the attack, a South Vietnamese column from the 1st Armored Brigade advanced down Highway 9 toward Tchepone. (Map 19) Operation LAM SON 719 had begun.
Because of security leaks, the North Vietnamese were not deceived. Within a week South Vietnamese forces numbering about 17,000 became
bogged down by heavy enemy resistance, bad weather, and poor attack management. Conflicting orders from I Corps headquarters and the airborne division delayed the reinforcement of a critical landing zone north of the highway, and the position was lost. The drive into Laos stalled. Before long the South Vietnamese were facing elements of five North Vietnamese divisions, as well as a tank regiment, two artillery regiments, and numerous antiaircraft battalions. Departing from the evasive tactics they had used a year earlier in Cambodia, the North Vietnamese had decided to stand and fight for their sanctuaries. Nonetheless, aided by heavy U.S. air strikes, including B–52s, and plenty of artillery and helicopter gunship support, the South Vietnamese inched forward and after a bloody, month-long delay, air-assaulted on March 6 into the heavily bombed town of Tchepone. This was the last bit of good news from the front.
By that time the North Vietnamese had counterattacked with Soviet- built 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 firebases, depriving South Vietnamese units of desperately needed flank protection. The South Vietnamese also lacked enough antitank weapons to counter the North Vietnamese armor that appeared on the Laotian jungle trails and were inexperienced in the use of those they had. U.S. Army helicopter pilots flying gunship and resupply

355

missions and trying to rescue South Vietnamese soldiers from their besieged hilltop firebases encountered intense antiaircraft fire. One pilot lamented that enemy gunners were “getting better because of all the practice we’ve given them.” Planners initially thought that the 101st Airborne Division and its attached units could provide all the helicopters
the operation needed; but as enemy resistance stiffened, Abrams had to shift more and more helicopters to northern I Corps, some from the Americal Division in southern I Corps, others from aviation units in II Corps, even from a 1st Cavalry Division element in III Corps that was about to leave Vietnam. When the availability rate of the UH–1C Huey gunship during LAM SON slipped to 40 percent, the USARV commander, Lt. Gen. William J. McCaffrey, put in an urgent call to the Department of the Army. He asked that all available AH–1G Cobra helicopters, the latest gunship in the Army’s arsenal, be airlifted to South Vietnam.
On March 16, ten days after Tchepone was taken, President Thieu issued the order to pull out, turning aside General Abrams’ plea for an expansion of the offensive to do serious damage to the trail. Command

Chopper Pick-up, Brian H. Clark, 1968

357

Withdrawal: The Final Battles

      As the Americans withdrew, South Vietnam’s combat capability declined. The United States furnished its allies heavier M48A3 tanks to match the North Vietnamese Army’s T–54 tanks 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-1968, for example, some forty-five allied infantry battalions were present in South Vietnam’s two northern provinces; in 1972, with U.S. infantry gone, only twenty-one battalions were in the same area. Artillery strength in the northern region suffered a similar decline, and ammunition supply rates fell as well. Similar reductions took place throughout South Vietnam, causing declines in mobility, firepower, in-

358

telligence support, and air support. 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. A South Vietnamese 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 South Vietnam, North Vietnam was preparing for its 1972 spring offensive. With the South’s combat capacity diminished and nearly all U.S. combat troops gone, the North sensed an opportunity to demonstrate the failure of Vietnamization, hasten the South Vietnamese Army’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 allies had plenty of warning of an impending attack. In December U.S. intelligence had started detecting enemy concentrations of armor and artillery farther south along the Ho Chi Minh Trail than ever before encountered, and analysts had also noted a dramatic increase in the number of North Vietnamese soldiers infiltrating into the South. By mid-January Abrams was so certain of his information that he was predicting a major conventional attack in which massed enemy formations and enemy armor and artillery operating in the open would play the decisive role. This gave confidence to those officials who believed in the efficacy of U.S. air power. In fact, as the winter wore on, air power advocates felt that a succession of “protective reaction” air strikes President Nixon had authorized in December had actually forestalled the expected offensive. While this point was controversial, all did agree that U.S. ground forces in Vietnam were no longer in a position to exercise influence over the battlefield. By March 1972 total military strength in the South had fallen to about 100,000, with one brigade, the 196th Light Infantry, at Da Nang, another, the 3d Brigade, 1st Cavalry Division, at Bien Hoa. The task of countering any offensive on the ground would fall almost exclusively to the South Vietnamese.

359

        The Nguyen Hue, or Easter, offensive began on March 30, 1972. Attacking on three fronts, the North Vietnamese poured across the demilitarized zone and out of Laos into northern I Corps, pushed eastward into the Central Highlands, and drove down Highway 13 toward Loc Ninh and An Loc, one of the traditional invasion routes to Saigon. Surprised by the ferocity of the attacks, the South Vietnamese fell back everywhere. The most devastating assaults took place in Quang Tri Province. (Map 20) While enemy artillery struck every firebase in the northern defense sector, infantry and armor quickly routed the 3d Infantry Division, formed just months before, and slashed their way toward Dong Ha. Momentarily held up by the 20th Tank Regiment, by May 1 North Vietnamese forces had taken Quang Tri City and the rest of Quang Tri Province and were threatening to move on Hue. In one month of battle, the South Vietnamese in northern I Corps had lost almost all their artillery and all but one of their M48s. The marines and rangers had also lost heavily, and several U.S. advisers had died. As refugees streamed south toward the dubious safety of Hue, South Vietnamese forces established a defense line at the My Chanh River on the Quang Tri–Thua Thien provincial border and President Thieu replaced the I Corps commander, General Lam.
Elsewhere, South Vietnamese losses were nearly as serious. Though the enemy attack in II Corps developed more slowly, by April 24 North Vietnamese forces had destroyed the 22d Division at Tan Canh and Dak To, seized control of northern Kontum Province, and were knocking
on the door of Kontum City. President Thieu removed another corps commander, leaving the senior adviser, John Paul Vann, a civilian, in command of II Corps and Kontum City braced for all-out assault. The III Corps area also was sorely threatened. Realizing too late that the main attack was developing in Binh Long, not Tay Ninh, Province, the South Vietnamese and their advisers were slow to reinforce the corridor down Highway 13. Loc Ninh fell to the 5th PLAF Division in a week, and a few days later enemy infantry and armor invaded An Loc’s northern neighborhoods and could not be ejected. The U.S. adviser with the South Vietnamese 5th Division thought defeat was near.
This was the grim situation, enemy pressure unrelenting everywhere and the contest in doubt, when, sometime during May, the battlefield on all three fronts began to stabilize. The change was barely perceptible at first, but slowly the enemy offensive ran out of steam. Much of the enemy’s difficulty turned out to be logistical. For the first time in the war huge amounts of fuel and ammunition were required to sustain the enemy’s fighting forces in South Vietnam. Those supply lines became targets of a renewed aerial offensive in both North and South Vietnam that isolated the Southern battlefield as never before. Every front felt the impact of U.S. air power. At Kontum City, with supplies and artillery running low, the North Vietnamese Army spent its infantry in city fighting until it was too weak to withstand a counterattack by the 23d Division. Harried by U.S. helicopters and tactical air strikes, enemy forces were soon in retreat toward Cambodia. An Loc was touch-and-go a little longer; but by mid-June, buttressed by air drops from U.S. Air Force C–130s, and massive B–52 bombing runs, the South Vietnamese made their stand at the city center, decimating the attacking formations. After several more desperate assaults, the enemy survivors slipped

Map 20

end of the offensive substantial parts of Quang Tri and Binh Long Provinces remained in enemy hands, while northwest Tay Ninh Province had also become safe enough for the Communists to reestablish COSVN headquarters there. In addition, there were new and disturbing signs of North Vietnamese penetration of the Mekong Delta to compensate for Viet Cong losses there to pacification. A rise in attacks on government outposts in the delta pointed to the fragility of pacification in this crucial arena. Looking at the country as the whole, on the other hand, CORDS officials insisted that the offensive had not undone the gains since 1968, at least not permanently. Although the measurements of hamlet security remained controversial and subject to interpretation, the trends seemed to suggest that government programs for security and rural development were well on the way to recovery by the end of 1972.
What had changed in 1972 were the tactics of the war, bringing new levels of destructiveness to the battlefield. Communist forces had made extensive use of armor and artillery. Among the new weapons in the enemy’s arsenal was the Soviet SA–7 handheld antiaircraft missile, which posed a threat to slow-flying tactical aircraft and helicopters and inflicted losses at Quang Tri City. The Soviet AT–3 Sagger antitank missile destroyed allied armor and bunkers in northern I Corps and at Tan Canh in II Corps. On the other hand, Army helicopter gunships, some of them newly outfitted with TOW (Tube-launched, Optically tracked, Wire-guided) antitank missiles, proved effective against North Vietnamese armor at standoff range. In their antitank role, Army attack helicopters were crucial to the South Vietnamese Army’s successes at An Loc and Kontum City, suggesting a larger role for helicopters in the future as part of a combined-arms team in conventional combat.
The other major development in 1972 was the decisive application of air power and the encouragement this offered to South Vietnamese

362

leaders facing a future without American ground forces. President Nixon’s
resumption of the bombing of North Vietnam during the Easter offensive and, for the first time, his mining of North Vietnamese ports, gave confidence to the belief that the South Vietnamese could count on U.S. air support in the years ahead. So did the intense B–52 bombing of Hanoi and Haiphong, the LINEBACKER II raids, in December 1972. But such pressure was intended at least in part to force North Vietnam to sign an armistice. If President Thieu was encouraged by the display of U.S. military muscle, the course of negotiations in Paris could only have been a source of discouragement. The long deadlock was broken in August, when North Vietnam, in the wake of its failed Easter offensive and under pressure from the Soviet Union to find a solution, dropped an earlier demand for Thieu’s removal. At the same time the United States gave up its insistence on North Vietnam’s withdrawal from South Vietnam. With that agreement, the talks hastened to a conclusion. 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 MACV 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 the South Vietnamese Army’s command structure—were withdrawn.
Between 1973 and 1975, South Vietnam’s military security declined through a combination of old and new factors. Plagued by poor maintenance and shortages of spare parts, much of the advanced equipment provided South Vietnam’s forces under Vietnamization became inoperable. A rise in fuel prices stemming from a worldwide oil crisis further restricted the South Vietnamese military’s use of vehicles and aircraft. Government 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 spare 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 R. 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 now became an all-out effort to conquer South Vietnam. Thieu, desiring to

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.

363

husband his military resources, decided to retreat rather than to reinforce the Central Highlands. The result was panic among his troops and a mass exodus toward the coast. As North Vietnamese forces spilled out of the Central Highlands, they cut off South Vietnamese defenders in the northern provinces from the rest of the country. (Map 21) Other North Vietnamese 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 held back the enemy offensive against the capital for a while, but not for long. As South Vietnamese leaders waited in vain for American assistance, Saigon fell to the Communists on April 30, 1975.
The time South Vietnamese forces bought near Saigon allowed the United States to complete a final evacuation from the capital. All day long on the twenty-ninth of April, Air Force and Marine Corps helicopters shuttled nearly 7,000 people, including the American ambassador, to U.S. Navy ships waiting off shore. Among the 5,600 non-American evacuees were South Vietnamese who were related to Americans or who faced a doubtful future because of the work they had done in Vietnam for U.S. agencies. Two U.S. marines were killed when North Vietnamese shells struck the compound of the former MACV headquarters that was serving as an evacuation site. Two pilots died when their helicopter went down at sea. These were the final U.S. casualties in Vietnam while the war still raged. When the last helicopter lifted off from the American embassy the next morning, taking with it a contingent of marine guards, the long American war for Vietnam came to a close.

An Assessment

       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 3 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 South Vietnam’s political shortcomings. Over a span of two decades, a series of regimes had failed to mobilize fully and effectively their nation’s political, social, and economic resources to foster a popular base of support. North Vietnamese conventional units ended the war, but insurgency and disaffection among the people of the South made that outcome possible.
The U.S. Army paid a high price for its long involvement in South Vietnam. American military deaths exceeded 58,000; of those, about two-thirds were soldiers. The majority of the dead were low-ranking enlisted men (E–2 to E–4), young men twenty-three years old or younger, of whom approximately 13 percent were African American. Almost a third of the deaths were caused by small-arms fire; but a significant portion, a little over a quarter, stemmed from mines, booby traps, and grenades. Artillery, rockets, and bombs accounted for only a small portion of the total fatalities. The deadliest year was 1968, followed by 1969 and 1967.

Map 21