In an effort to prevent French Indochina from falling to Communism, the United States in 1950 began to grant military aid to French forces in Southeast Asia, including those in Vietnam. This commitment was at the outset minor, only a fragment of the worldwide Military Assistance Program, but over the years it was destined to grow in size and complexity until it overshadowed other commitments and became a test of American resolve.
In Vietnam the United States acted at first to help the French regain military control in the face of a Communist - dominated nationalist movement. When a climate for true self-determination could be achieved, it was hoped that France would grant the nation independence.
Before the United States was deeply committed, the conflict in Vietnam had lost the complexion of colonial war and emerged as a struggle for survival of a small nation in the pattern of what the Communists call wars of national liberation. It was complicated by similar but less well-organized Communist aggression against the neighboring countries of Laos and Cambodia, by an ideological split in the Sino-Soviet Communist bloc, and by a possibility that as a testing ground between Communists and non-Communists it might explode into broader war and bring the world powers into direct conflict.
Role Of The United States Through The Geneva Accords
Since the conflict from the start involved primarily ground operations, officers and men of the U.S. Army made up the bulk of the U.S. military forces committed. Only a few Americans were involved at first, constituting the Military Assistance Advisory Group, Indochina, subsequently redesignated Military Assistance Advisory Group, Vietnam. The task was limited initially to administering financial and military aid to the French and those Vietnamese forces loyal to the French - sponsored government of the emperor, Bao Dai.
This situation prevailed for almost four years as the French continued a long-term effort to wrest control of the countryside from Communist forces known as the Viet Minh under the veteran Communist leader, Ho Chi Minh. The Viet Minh early had proclaimed a separate government professing jurisdiction over the entire country, a self-styled Democratic Republic of Vietnam. Provided extensive military assistance from China, including advisers and technicians, the Communists had established control over most of the northern and central provinces, leaving to the French and the Bao Dai government little more than the principal cities and a few provinces near the city of Saigon in the south.
Unwilling to grant the Vietnamese full independence, the French were never able to rally widespread support from the populace. Beset by opposition in France to a colonial war and lacking the military forces to meet Communist insurrections in all of Indochina, the French in 1954 agreed to an international conference to be convened at Geneva to negotiate a settlement.
The discussion at Geneva involved nine nations, including the United States, France, Great Britain, the Soviet Union, and Communist China, representatives of Laos and Cambodia, and separate delegates from the Democratic Republic of Vietnam (Ho Chi Minh) and the State of Vietnam (Bao Dai). The conference produced what became known as the Geneva Accords, a signed cease-fire agreement and an unsigned Final Declaration, with separate documents covering Laos and Cambodia. For Vietnam, the Geneva Accords directed a military disengagement based on a temporary demarcation line across the narrow waist of the country at the 17th parallel. The territory north of the line was to be administered by the Viet Minh, that south of the line by the French. Military forces were to regroup on either side of a demilitarized zone ten kilometers wide, while civilians were to be free to choose between the two zones. No increase in foreign military aid was to be made. To reunite the country, Vietnam-wide elections were to be held two years later.
The Vietnamese government in the south, objecting - as did Ho Chi Minh's government - to any division of the country and convinced that free elections were impossible in the north, refused to accept these two provisions as binding. The United States in turn declined to endorse the decisions but agreed to abide by them and to forego use of force to disturb them so long as others did the same. In regard to elections, the United States noted its long commitment to achieving unity in divided countries through elections supervised by the United Nations.
Early Growth Of The Insurgency
As an armistice settled over what became, unintentionally but actually, two Vietnams - North and South - over 800,000 North Vietnamese moved to the south. Approximately 100,000 South Vietnamese moved north, most of them active Viet Minh insurgents, while Ho Chi Minh called on a political cadre of the Viet Minh to remain in the south in preparation for what he expected would be a sure Communist victory in the elections. The Viet Minh also retained control of their base areas, the secret zones they had established in the south.
The United States, meanwhile, acted to create a bulwark against further Communist expansion in Southeast Asia by preserving the southern half of Vietnam outside the Communist sphere. Approximately 400 American advisers, already present in Saigon at the time of the Geneva Accords, remained to assist the South Vietnamese government. Through them the United States worked to improve a South Vietnamese Army of some 200,000 men that had fought with the French and to provide extensive economic aid to the government, which with promise at last of full independence had gained a strong premier in Ngo Dinh Diem. Convinced that a large majority of Vietnamese desired a free nation outside the bonds of totalitarian Communism and that by the example of successful resistance to Communism in Vietnam other free Asian peoples would be encouraged to resist, the United States under four successive presidents - Eisenhower, Kennedy, Johnson, and Nixon - worked to make the institutions of a free society available to that half of the nation to which circumstances afforded access.
Among the first obstacles was the inevitable stigma attached to a government originally sponsored by a colonial power, as well as the problem of convincing a people exploited by foreigners through much of their history that the United States had no colonial designs. In a country where a majority of the people were Buddhists, resentment was strong against heavy representation in the government of a Catholic minority, many of whom were refugees from North Vietnam. Two relatively small but powerful religious sects, the Cao Dai and the Hoa Hao, exerted strong political pressures even after the South Vietnamese Army succeeded in establishing authority over autonomous military forces the sects had long maintained. In the sparsely populated plateaus and mountains of the interior - the Central Highlands - tribal groups known as the Montagnards continued a long resistance to governmental authority. The basically agrarian South Vietnamese economy, lacking the industry and minerals of the north, was near chaos. Long under Viet Minh control, much of the countryside was devoid of government services; and corruption that had flourished under colonial rule was rampant. The emperor, Bao Dai, was of no assistance, having deserted his country to reside abroad.
Ruling autocratically, Premier Diem managed to bring a measure of order to the country, and the economy improved. Late in 1955 he conducted a national referendum in which the people chose between him and the absent emperor. Winning the referendum handily, he proclaimed a republic with himself as president. He outmaneuvered dissident Army officers seeking to seize power, defeated a strong band of Saigon gangsters, the Binh Xuyen, resettled refugees from the north, and made a start on a program of land reform.
Early in 1956, shortly before the time designated by the Geneva Accords for general elections, the French pulled the last of their forces out of Vietnam. President Diem then reiterated South Vietnamese objections to Vietnam-wide elections, again declaring that free expression was impossible in the north under a totalitarian regime. The United States backed this position with the notice that "there must first be conditions which preclude intimidation or coercion of the electorate."
Since the Viet Minh anticipated some support in the south and were sure of their controlled electorate in the more populous north, they had allowed the Communist insurgency in the south to lie quiescent while they awaited triumph in the elections. They were preoccupied for the moment in any case with asserting their authority in the north, crushing a popular revolt, and conducting a reign of terror to bring agricultural lands under state control. When the elections failed to come off, it took time for the Viet Minh to reactivate the insurgency, since the organization they had left behind in the south had to be rebuilt and strengthened.
Called by the South Vietnamese the Viet Cong, a contraction meaning Vietnamese Communist, the insurgents in the south gradually increased their numbers through a campaign of propaganda and coercion. At the same time the North Vietnamese government made the decision to bring down the South Vietnamese government by aggression, and in 1958 began to infiltrate political cadres and military reinforcements from the north. Terrorism, assassination, sabotage, abduction, and attacks on civil guard and local defense units mounted. In late 1960 North Vietnam sponsored a National Front for the Liberation of South Vietnam, designed to attract other nationalists In addition to Communists, a device practiced by the Viet Minh in earlier days with considerable success.
Organized and trained to counter a conventional invasion, the South Vietnamese Army was ill prepared to deal with insurgency, and the limited numbers of U.S. advisers were hard put to provide the comprehensive assistance needed. The task was complicated when the French in 1955 began to pull out their forces and started a precipitate transfer of American military equipment to the South Vietnamese Army. To bring some order to the process, the United States early in 1956 sent 350 more military men to form the Temporary Equipment Recovery Mission. Aware of the proviso of the Geneva Accords prohibiting increased foreign military strength, the United States maintained that these men replaced departing French advisers. Four years later the International Control Commission, set up to police the Accords, approved expansion of the Military Assistance Advisory Group, Vietnam, to 685 spaces, thus accommodating most of the 350.
The American advisers were concentrated in Saigon, helping the Vietnamese with high-level planning, training, and logistical organization. Only in early 1960, as the insurgency continued to increase and it became apparent that the South Vietnamese Army had to be drastically improved, did President Diem agree to assigning U.S. advisers to field units down to battalion level. Even then, because of the limited number of advisers, assignments had to be selective and temporary.
While the Viet Cong insurgency was expanding, President Diem fell more and more under the influence of members of his family, whom he had placed in high positions, and the government grew remote from the needs and desires of the people. Many South Vietnamese were alienated because Diem continued to rule autocratically, failed to involve the people in government at the local level, moved slowly in land reform, employed arbitrary policies in military and civil administration, and used oppressive police methods. Although Diem rationalized his policies as either necessary to defeat the insurgency or correctable only after national security was achieved, dissatisfaction with his rule spread.
Limited Increase In U.S. Commitment
During 1961 the Viet Cong campaign of murder and abduction continued to increase, directed not only at local officials but often at their families and at the civilian population in general. With such means was awe of the Viet Cong induced, and a belief spread that the government was incapable of protecting the people. Supported at this point by aid from both China and the Soviet Union, the Viet Cong by the fall of the year had achieved enough power to threaten the existence of the Diem regime.
Seriously perturbed by these developments, President Kennedy reviewed in detail the reports and recommendations of a number of special missions sent to study the extent of the crisis. Conscious of the violence already done the Geneva Accords by North Vietnamese infiltration and support of the Viet Cong, he finally decided to increase U.S. support, but to stop short of committing combat troops. With this decision, the U.S. commitment grew in 1962 to more than 11,000 men, two-thirds of them U.S. Army.
In February 1962 the U.S. Military Assistance Command, Vietnam, was established in Saigon with General Paul D. Harkins as commander. This new command, which eventually absorbed the Military Assistance Advisory Group, was a subordinate unified command under the operational control of the Commander in Chief, Pacific, who was in turn responsible to the Secretary of Defense through the Joint Chiefs of Staff. General Harkins also directly commanded the Army component.
During 1962 the increase in U.S. strength more than tripled the number of officers and men directly engaged in the advisory effort, and for the first time made possible the attachment of advisers to most South Vietnamese Army units in the field. Men of the U.S. Army Special Forces also were introduced to train Civilian Irregular Defense Groups, formed among the Montagnard tribesmen in the highlands and other South Vietnamese in remote border regions.
The Communist threat to the highlands had been growing fast in conjunction with a Communist movement, supported by the North Vietnamese, in neighboring Laos. In establishing loose control over large portions of Laos, the Communists had firmly secured a wide strip along the South Vietnamese frontier through which they built trails and roads leading from North Vietnam around the flank of the demilitarized zone into South Vietnam. Known collectively as the Ho Chi Minh Trail, these supply routes contained logistical bases and relay stations adequate for a sustained war effort by large forces.
Manning fortified outposts and patrolling extensively, the Civilian Irregular Defense Groups with their Special Forces advisers sought to disrupt a steady infiltration of North Vietnamese from Laos into South Vietnam and to prevent a Communist takeover in the highlands. Even though interested world powers achieved a semblance of peace in Laos with another Geneva conference in mid-1962, the Communists retained possession of - the border zone and continued their build-up. Some 60,000 South Vietnamese, trained during 1962 and 1963 by the U.S. Army Special Forces, nevertheless held their positions in the highlands and elsewhere along the frontier.
The role of the advisers throughout Vietnam was difficult and challenging. These were men charged with developing leadership among a people whose colonial rulers had for long years discouraged leadership. These were men who had to adapt swiftly to social, political, and economic conditions foreign to their experience; to communicate their ideas and military acumen to Vietnamese counterparts separated from them by a substantial language and cultural barrier; and to entrust their own welfare and safety to foreign troops often unproven and sometimes infiltrated by an enemy almost impossible to detect. All their goals they had to achieve in an advisory rather than a command role.
When U.S. strength increased in 1962, most of the American effort went into a new task of operational support for South Vietnam armed forces, with special attention to mobility, communications, intelligence, and logistics. Easily the most dramatic and portentous development was the introduction of the helicopter to provide Vietnamese Army units, heretofore mainly roadbound and thus highly vulnerable to ambush, a new mobility.
The first helicopter to fly in large numbers in South Vietnam was the CH-21, the Shawnee, followed in 1963 by the faster and more versatile UH-1, the Huey. The helicopter became the symbol of a new kind of war, a checkerboard campaign in which units might be picked up and set down swiftly almost anywhere from the highland plateaus and jungle-canopied mountains to the densely populated rice-growing regions of the coast and the Mekong Delta. An original assignment of one helicopter company to each of four Vietnam Army corps gradually grew to one per division. As the enemy reacted by bringing in more antiaircraft guns, armed versions of the Huey were added.
By the spring of 1963 South Vietnam had made considerable progress in the military struggle, but the political situation had worsened. Continuing governmental repression, coercion, favoritism, and corruption alienated more and more of the people. The ambassador and other U.S. representatives pressed for reforms, but to little avail. After the government's serious mishandling of a nationwide demonstration by Buddhists in mid-1963, the United States withheld subsidies for imports and for the Vietnam Army Special Forces, which President Diem had used to attack Buddhist pagodas.
On 1 November 1963, a military junta of senior South Vietnamese officers staged a coup d'etat in which the president and his brother Nhu were killed. There followed a year and a half of political instability, uncertainty, and disintegration of government control that the Viet Cong exploited to the fullest. Despite a gradual American build-up to approximately 23,000 men (not quite two-thirds Army) that afforded additional operational support and provided many more advisory teams for provinces and districts, the Viet Cong increased their strength to approximately one hundred thousand, of which about one-third were "main force" troops (first-line combat soldiers organized in battalions and regiments). The added strength included infiltrated North Vietnamese Army regulars.
In much of South Vietnam the Viet Cong were sufficiently in control to levy taxes in rural regions, and even though government troops might control many areas in daylight, it was generally accepted in much of the countryside that "the night belongs to the Viet Cong." A government program to relocate people in supposedly secure "strategic hamlets" all but collapsed. For the first time Viet Cong units launched numerous daylight attacks, and South Vietnamese casualties increased sharply. Although U.S. troops continued to serve only in advisory and support roles, U.S. losses also rose: 42 U.S. Army troops were killed, for example, in 1963; in 1964, 118 died.
Communist attacks against U.S. facilities were also mounting. In August 1964 North Vietnamese patrol boats engaged U.S. destroyers in the Gulf of Tonkin. In retaliation, President Johnson ordered air strikes by U.S. Navy planes against North Vietnamese patrol boats, their bases, and supporting facilities in North Vietnam. The Congress at this point passed a resolution authorizing the President to take necessary measures to repel attack against U.S. forces and to prevent further aggression in Southeast Asia.
Growing U.S. Commitment
Beginning early in 1965, the Viet Cong, reinforced by North Vietnamese Army units, opened a series of savage assaults. Under attacks that destroyed on an average the equivalent of a battalion a week, the South Vietnamese Army began to crumble. Leadership failed. Desertions increased. In the delta and Central Highlands the Communists demonstrated their strength by seizing and temporarily holding some district capitals. A Communist push from the highlands to the sea to cut South Vietnam in half and isolate Saigon appeared in the offing. The morale of the people dropped sharply, and some observers gave the nation no more than six months to live.
Having reaffirmed U.S. commitment to South Vietnam upon taking office after the death of President Kennedy, President Johnson viewed the situation with grave concern. When in February 1965, the Viet Cong attacked a U.S. compound and helicopter base in the Central Highlands, killing eight Americans, the President ordered retaliatory air strikes against selected military targets in North Vietnam. He also directed that dependents of U.S. military and government personnel be evacuated from South Vietnam, sent to the country a Hawk air defense battalion, and authorized U.S. Air Force jets to assist South Vietnamese Army units in emergencies. Amid continuing terrorism against U.S. installations, including the explosion of a bomb at the U.S. Embassy in Saigon, and mounting evidence of North Vietnamese support of the Viet Cong, the President ordered sustained bombing of military targets in North Vietnam in hope of bolstering South Vietnamese morale, reducing North Vietnamese infiltration into the south, and making North Vietnam pay a higher price for its aggression.
To guard American installations, the President ordered the first U.S. ground troops to Vietnam, two U.S. Marine Corps battalions that arrived in March at Da Nang, the country's second largest city. A U.S. Army military police battalion arrived two weeks later at Saigon. In early April the President ordered two more Marine battalions and an air squadron to Da Nang and authorized the marines to expand their operations beyond their defensive perimeters. This marked the start of a short-lived "enclave strategy," under which U.S. troops were to secure selected areas, free Vietnamese troops for other operations, and demonstrate American resolve.
In May the 173d Airborne Brigade arrived to provide security for an air base at Bien Hoa, north of Saigon. The next month U.S. B-52 strategic bombers launched the first of what came to be continuing raids against entrenched enemy bases in remote regions of South Vietnam. The B-52's were based on Guam and later in Thailand. Under new authority granted by President Johnson to use ground troops when necessary to strengthen the South Vietnam Army, the 173d Airborne Brigade late in June conducted the first U.S. ground offensive of the war, a brief incursion with Vietnam Army units into War Zone D, an enemy sanctuary close to the Bien Hoa air base.
Since the situation continued to deteriorate, President Johnson concluded that only by commitment of large numbers of U.S. combat troops could Communist takeover of the Republic of Vietnam be prevented. Responding to a request by the South Vietnamese government, the President in mid-July ordered two more U.S. Army brigades to Vietnam, the vanguard of some 180,000 troops that were to reach the country by the end of the year.
As the U.S. build-up began, from the chaos in Saigon a government at last emerged that was to provide a measure of stability unseen since Diem's overthrow. It was a military government with an Army general, Nguyen Van Thieu, as chief of state, and an Air Force marshal, Nguyen Cao Ky, as premier, but one that gave promise of an eventual return to representative rule.
Logistical Build-Up
The U.S. combat troops arriving in South Vietnam at first occupied and secured key positions and existing U.S. installations and began preparing a logistical base for whatever additional troops might be needed later. Creating a logistical base was particularly difficult but essential in a country where the only major port, Saigon, was already clogged with shipping, where the enemy continually made roads unusable, and where the only major railroad had ceased to function. Ports, warehouses, cantonments, airfields, maintenance facilities, communications - all had to be built where there was at the beginning almost nothing.
The logistics system expanded swiftly until at the end of 1967 the Army was supporting more than 1.3 million men, including South Vietnamese armed forces, troops of other free world nations, and a number of U.S. civilian agencies. An average of 850,000 short tons of supplies arrived each month. Troops consumed 10 million field rations each month, expended 80,000 tons of ammunition, and used 80 million gallons of petroleum products. Manning a highly sophisticated military machine, the individual American soldier in Vietnam received about 96 pounds of supply support per day, more than twice the amount per man in the Pacific theaters of World War II.
The engineer construction program in particular provided tangible and dramatic evidence of the extent of the logistical effort. The United States built completely new ports or vastly expanded existing facilities at Cam Ranh Bay, Qui Nhon, Nha Trang, Vung Tau, Da Nang, and Saigon, thereby making possible discharge and ready supply to all portions of the country in which U.S. Army units operated. Engineers paved 4 million square yards for airfields and heliports, providing the country with these facilities in a density seldom found elsewhere in the world. They constructed 20 million square feet of covered and open storage facilities, and half a million cubic feet of refrigerated storage, the latter immensely important in a country with a year-round tropical climate. At Dong Tam in the Mekong Delta, millions of cubic yards of sand were dredged from the bottom of an arm of the Mekong River to create a 600-acre island base amidst the rice paddies.
Maintenance in the presence of heat, humidity, and monsoon rains posed an ever-present problem. It was solved at first by improvisation, long hours of extra maintenance work, adaptation of the Red Ball Express concept of World War II to speed critical items from the United States by air, and sending general support maintenance units forward to assist direct support units. In the end new inspection methods and new techniques of maintenance management, including use of complex electronic computers housed in air-conditioned buildings, enabled a return to more normal maintenance procedures.
Never before had an army been served by more comprehensive and effective medical support than was the U.S. Army in Vietnam. A casualty was seldom more than half an hour by air from a hospital, and the mortality rate among wounded receiving hospital attention was cut to less than 1 percent, lowest in the history of warfare. The old bane of tropical climates, malaria and intestinal diseases, nevertheless continued to plague the Army, despite modern advances in preventive medicine. Medical assistance to the Vietnamese, who were woefully short of doctors, nurses, and hospitals, was freely administered.
The organization for logistical support embraced five principal commands, four of them to handle specialized support for aviation, engineers (primarily construction), Hawk missiles, and hospitals, and the fifth, the 1st Logistical Command, to provide all other support. The last operated on an area basis keyed to four corps tactical zones established early by the South Vietnamese Army. Operating in the chain of command of the United States Army, Pacific, the Army in Vietnam obtained additional logistical support from U.S. bases in Japan and Okinawa.
Early U.S. Operations
As the immense logistical effort grew, the increase of U.S. combat troops proceeded apace and U.S. forces were soon engaged in conflict with the Viet Cong and with regular units of the North Vietnamese Army. The latter began to appear early in 1965 in regimental and later divisional formations.
The strategy adopted by the U.S. commander, General William C. Westmoreland, who had succeeded General Harkins in the summer of 1964, was holding action combined with spoiling attacks to keep the enemy off balance and gain the time needed to build base camps and logistical facilities. This accomplished, U.S. units with assistance from the South Vietnamese Army were to engage in search and destroy operations designed to find and eliminate Communist main force units and their base areas rather than to seize and hold territory permanently. These operations were to provide a shield behind which other South Vietnamese Army and U.S. forces could operate against the local guerrillas in support of a rural pacification program, designed to bring security and government control to the countryside. The South Vietnamese Army also was responsible for defending government centers, including the cities and the provincial and district capitals.
It was early agreed that U.S. support in the I Corps Tactical Zone, composed of the fire northernmost provinces, was to be primarily a Marine Corps responsibility; the U.S. Army was to operate mainly in the II and III Corps zones, which embraced the Central Highlands, adjacent coastal regions, and the area around Saigon. South Vietnamese Army troops were to retain primary responsibility for the delta region of the IV Corps Tactical Zone. The U.S. Air Force was to provide tactical air support and airlift while continuing the B-52 bomber campaign and, along with U.S. Navy carrier-based planes, the strategic bombardment of North Vietnam. Air operations against North Vietnam and naval patrols of the U.S. Seventh Fleet were under the direct control of the Commander in Chief, Pacific, rather than the U.S. Military Assistance Command, Vietnam.
U.S. resources still were meager when in late summer of 1965 the enemy build-up in the Central Highlands began to reach alarming proportions, apparently presaging the long-expected attempt to push through to the sea and cut South Vietnam in two. With only three U.S. Army brigades available at the time, General Westmoreland nevertheless thought it better to risk a setback at the start than to allow the concentration in the highlands to go unchecked. Leaving two brigades to protect Saigon, he sent a third to An Khe, midway between Qui Nhon on the coast and Pleiku, deep in the highlands, to stake out and secure a site for a base camp for the 1st Cavalry Division (Airmobile), scheduled to arrive in September. When the division reached Qui Nhon, its combat troops flew to An Khe in their helicopters within hours.
The airmobile concept faced a battlefield trial a few weeks after the arrival of the 1st Cavalry Division. South Vietnamese reinforcements had broken the siege of a Special Forces camp at Plei Me near the entrance to the Ia Drang valley southwest of Pleiku, but intelligence revealed that three North Vietnamese regiments were regrouping in the vicinity for renewed attack. General Westmoreland ordered the cavalry division into the fight to find and destroy the enemy regiments.
The operation lasted for over a month. The enemy stood and fought in densely wooded mountainous country close to the Cambodian border, using every tactic at his disposal: ambush, attack and counterattack, night infiltration, "hugging" (sticking in close to U.S. troops to forestall air and artillery strikes), and human wave assaults. In the end, American troops killed more than 1,300 North Vietnamese and sent the survivors fleeing to safe havens across the border. The 1st Cavalry Division lost 300 men killed.
Although it had proved impossible to encircle and destroy the entire enemy force-something that was to frustrate many a U.S. unit in the years to come - what became known as the Ia Drang valley campaign thwarted the enemy's build - up in the highlands, proved the validity of the airmobile concept under conditions existing in Vietnam, and confirmed the ability of U.S. troops to defeat the enemy even in inhospitable jungle terrain. The Communists relied on surprise, mobility, and mass, but these they could achieve only by carefully planned movements that took weeks to execute, whereas an entire brigade of the airmobile division could move into battle hours after an alert.
As foreshadowed by earlier South Vietnamese Army operations with U.S. helicopter support, the airmobile concept had opened a new chapter in the history of land warfare, the helicopter introducing for the first time a flexible third dimension to the battlefield. In the continuing U.S. build-up, the Army placed heavy emphasis on providing enough helicopter companies to assure airmobile support for all infantry units. The helicopter companies were to provide transportation not only for long distance moves, but also for maneuvers during an engagement over short or long distances, superior firepower either from gunships or from artillery lifted by helicopter, superior logistical, medical, and intelligence support, and flexible control through aerial command posts.
The Nature Of The War
Within three years, U.S. military strength gradually built up in South Vietnam from less than 25,000 to almost 500,000. U.S. Army forces grew to include two corps headquarters, seven divisions, two separate infantry brigades, an airborne brigade, and an armored cavalry regiment. U.S. Marine forces increased to two divisions and a separate regiment.
Regular South Vietnam Army forces meanwhile rose to over 340,000 men, and the militia - called Regional and Popular Forces - to 300,000. The Republic of Korea furnished 48,000 men, including two divisions and a marine brigade; Thailand, a division; Australia, a brigade; the Philippines and New Zealand, smaller units. Some form of nonmilitary aid was provided by thirty-five other nations. The total support rendered South Vietnam by nations other than the United States was greater than that given South Korea under the United Nations flag.
Despite nearly 180,000 Communists reported killed during these three years and almost 70,000 captured, the Communists still managed to build their strength to 240,000, including main force units, local guerrillas, and supporting troops. This feat they accomplished by stepping up recruitment in the south and by sharply increasing the numbers of North Vietnamese regulars. As their casualties rose, Viet Cong main force units often were kept up to strength only by incorporating North Vietnamese replacements.
While not foreign to American experience, the nature of the war in Vietnam was by any standards unusual. It was a war without clearly defined front lines. The enemy could be anywhere and everywhere and often indistinguishable from the native population. Without the usual standards for measuring success or failure, substitutes had to be devised - how many Communists killed by "body count," how many hamlets and villages "pacified," how many miles of essential highways open to travel. These provided some but no certain indication of progress.
It was a war with no shot fired at Fort Sumter, no sinking of the Maine, no Zimmermann telegram, no Pearl Harbor, no massed armies crossing the 38th parallel to afford a clear call for American involvement. Toward this war some Americans developed a new form of isolationism. Some feared becoming mired in war on the Asian mainland, others accepted the Communist-promoted view that an aggressive North Vietnam was in reality a "Little Belgium," much sinned against by American power; and still others wearied of a struggle that appeared to afford no quick or decisive end.
It was the first war that Americans viewed in their homes on television; and in base camps in Vietnam U.S. troops also had television. Many men flew to war by commercial aircraft. U.S. civilians of the State Department, the U.S. Information Agency, the Central Intelligence Agency, and the Agency for International Development were involved close alongside the soldiers. There was no censorship of the soldier's mail nor any involuntary censorship of the American press. The Army contracted some of its construction work with U.S. civilian firms. The American commander, General Westmoreland, had no command authority over the South Vietnamese Army and most allied troops. In an effort to keep the war from spreading, neither American nor allied troops pursued the enemy into Cambodia and Laos or beyond the demilitarized zone between South and North Vietnam, even though the enemy maintained bases there and brought supplies through the Cambodian port of Sihanoukville and over the Ho Chi Minh Trail complex through Laos. In hope of promoting negotiations, the U.S. proclaimed intermittent halts in the bombing of North Vietnam. Both sides declared truces at Vietnamese holiday periods.
How the U.S. Army fought the war was also unusual. All U.S. divisions and separate brigades had fortified base camps. From these they might operate in neighboring districts on security and pacification missions. At other times, leaving a security and housekeeping cadre behind, they might shift far afield to construct a temporary base camp and forward fire support bases from which artillery could support far-ranging search and destroy operations. On many of these missions, particularly in the thick jungles of the highlands, companies and battallions were far from any road or trail and wholly dependent upon the helicopter for resupply and evacuation. If fire support bases came under attack, artillerymen often had to employ their pieces in point-blank fire. Longrange patrols on which small groups of men might be away for several days were common. Ambush and counterambush were familiar tactics on both sides.
In a war fought with modern weapons in populated areas, property destruction and civilian casualties, which occur in any armed conflict, were inevitable. The enemy used terrorism and murder as instruments to coerce the people; the most notable instance was the massacre of nearly 3,000 civilians during a temporary occupation of the old imperial capital of Hue in 1968. Despite strong emphasis by the U.S. command on avoiding civilian losses, U.S. units in a few instances experienced serious lapses of discipline, as at the village of My Lai in 1968 when a large number of civilians were killed.
The helicopter and radio communications were the two essential ingredients in U.S. conduct of the war. There were, too, sophisticated weapons and items of equipment-troop and cargo-carrying C-123'S, C-130'S, and CV-2'S, the light, automatic M16 rifle; the recoilless rifle; a one-shot antitank rocket; the claymore mine that was activated electrically and spewed hundreds of dartlike projectiles; "beehive" artillery projectiles, and armored personnel carriers modified to serve as fighting vehicles, some of them equipped with flame throwers; the Patton (M48A3) tank. There were also chemical defoliants and Rome plows, the latter bulldozers equipped with a special blade capable of demolishing all but the giants of the forest, used, as were defoliants, to deny the enemy and his base camps the concealment of the jungle. The troops also employed a powerful grenade-launcher firing a 40-mm. projectile; highly complex electronic sensors; HueyCobra helicopter gunships; and the Sheridan armored reconnaissance vehicle, equipped with a 152-mm. gun. In sharp contrast to the sophistication of other items, barbed wire and the sandbag were used as extensively as in World War I.
The enemy also had excellent weapons, mainly Chinese Communist copies of Soviet models. In the automatic AK47 rifle he had an individual weapon respected by both sides. He had an ample supply of mortars and heavy rockets, but other than along the demilitarized zone he employed almost no artillery and, except in defense against U.S. air strikes on North Vietnam, no aircraft. He also had recoilless rifles and a Chinese version of the claymore mine, and he was a master of the booby trap, which included explosives and sharpened bamboo spikes called punji stakes. In the antiaircraft defense of North Vietnam, he employed Soviet-supplied surface-to-air missiles.
The ability and morale of the American soldier were remarkable. Better educated than the soldier of earlier generations, both in civilian schooling and military training, he was conscious of the excellent medical, logistical, and fire support available to him. Although individual fights might be as fierce and as harrowing as any ever fought in any war, there were sometimes long intervals between engagements, and, except along the demilitarized zone, the constant nagging dread of enemy shelling was less pronounced than in earlier wars. Then too the knowledge that his tour would end in a year was a strong morale factor. Fully integrated with white troops, Negro soldiers proved their worth and, in retrospect, revealed the illogic of earlier segregation practices, however reflective of the nation's social system. Only late in the war, as the United States began to withdraw from Vietnam, did serious morale problems arise, a not unusual development when the combat role of an army decreases.
The Communist soldier, too, was accomplished; he had infinite patience and stamina, and he could subsist for long periods on a diet that to a westerner would have been debilitating. Although thousands defected to the South Vietnamese side under a government-sponsored Chieu Hoi (open arms, or amnesty) program, continued recruitment or impressment and North Vietnamese reinforcement made up for these as well as for the enemy's other losses.
The Military Campaign
After the U.S. victory in the Ia Drang valley, General Westmoreland for the remainder of 1965 and well into 1966 proceeded with his plan to keep the enemy off balance while building base camps and logistical resources. This plan involved search and destroy operations to protect the logistical bases under construction along the coast and the base camps for incoming U.S. units in the provinces near Saigon. It also involved another campaign to disperse an enemy build-up in the highlands. By midyear of 1966 progress was such that the enemy had become reluctant to mass for large-scale attack and Ho Chi Minh had proclaimed a strategy of protracted war, thus tacitly admitting that a quick military victory had eluded him.
U.S. forces at this point entered a new phase of operations, a prolonged offensive aimed at finding and annihilating the enemy's main force units and invading and destroying his long-established base areas, or secret zones. South Vietnamese Army units turned more of their attention to making the countryside secure in support of the pacification program.
In the II Corps zone, largest but least populous of the four tactical zones, U.S. operations had two basic objectives. One was to eradicate main force units from the rice-rich flatlands along the coast, denying the enemy this source of food and, by a sustained presence, providing a shield for pacification. The other was to maintain mobile forces in the sparsely populated Central Highlands that, by shifting here and there as the enemy was found, could prevent him from establishing control over the region as a base for operations against the northern provinces and the coastal plain. The troops in the highlands also afforded a reserve force to thwart the enemy's strikes against the Special Forces camps and other outposts along the frontier, from which the South Vietnamese harassed North Vietnamese infiltration routes into the country.
In early summer of 1966, sizable enemy units were again returning to the highlands and there were indications that another attack was forming to hit the Special Forces camp at Plei Me. When contingents of the 25th Infantry Division, 1st Cavalry Division, and 101st Airborne Division met the enemy, he stood and fought, oftentimes from sturdy bunkers located on advantageous hilltops. Only after fighting that lasted through much of August did the enemy finally withdraw across the border, leaving behind over a thousand dead.
As additional U.S. forces arrived in Vietnam, the 4th Infantry Division constructed a base camp in the Central Highlands near Pleiku and built a road deep into the western highlands to within a few miles of the Laotian frontier. The Communists reacted with sharp attacks, primarily against the 4th Division's fire support bases, in which they lost approximately 700 killed; but in general the enemy avoided prolonged fighting and fell back behind the border whenever he was seriously threatened.
With the 4th Division present in the highlands, the 1st Cavalry Division and a brigade of the 101st Airborne Division were free to concentrate on sustained operations in the coastal provinces. By late fall of 1966 they had broken the enemy's hold on this agriculturally rich region. One operation of the 1st Cavalry Division in conjunction with Korean and South Vietnamese units ended in a classic encirclement maneuver in which more than 2,000 Communists were killed. Shattered remnants of a North Vietnamese division fled into mountains to the northwest.
In the provinces near Saigon, the III Corps zone, American strength had increased to the point where operations could be conducted in an effort to drive the enemy away from the environs of Saigon into his secret zones, then destroy them. The first began in January 1966, when the 1st Infantry Division struck to eliminate a Viet Cong regional headquarters in the Ho Bo Woods, about 25 miles northwest of Saigon and close to an enemy stronghold known as the Iron Triangle. As was so often to be the case, the enemy escaped, in this instance through an elaborate underground tunnel system. Beginning in February, the 1st Division and contingents of the 25th invaded the enemy's War Zone C, 75 miles northwest of Saigon along the Cambodian border, and War Zone D, 40 miles north of the capital. Fighting was sporadic as the Viet Cong fled across the frontier, but U.S. troops found and destroyed large underground supply caches and training installations.
Possibly because of these sweeps or in an effort to open up infiltration routes, the enemy massed a division in the vicinity of a Special Forces camp at Loc Ninh, close along the Cambodian border, seventy-five miles north of Saigon. In a series of engagements involving thrusts and counterthrusts over a period of two months, the 1st Division killed close to a thousand of the Viet Cong and drove the rest across the Cambodian border.
In the fall of 1966, a sweep into a big rubber plantation in War Zone C by the 196th Infantry Brigade provoked a counterthrust by a Viet Cong division. Elements of three U.S. divisions, the 173d Airborne Brigade, and the 11th Armored Cavalry Regiment were quickly committed in the first U.S. operation of the war to be controlled directly by a corps headquarters. Yet despite the large numbers of troops engaged, the fighting was, as it had been everywhere, at the squad and platoon level. Over a thousand of the elusive enemy eventually were killed, but the Viet Cong's ability to fade away when confronted with American strength and firepower made campaigning here and elsewhere tedious and often exasperating.
As 1966 drew to an end, the fact that the enemy could not be found in large numbers in the II and III Corps zones was frustrating but at the same time proof that U.S. and South Vietnamese Army units had dealt the Communists telling blows. Early in 1967 the North Vietnamese began a build-up of several divisions in and just south of the demilitarized zone, apparently in an effort to draw U.S. strength from the south. Along with the build-up, heavy artillery fire was directed against U.S. Marine Corps positions.
The Pacification Program
Since U.S. and South Vietnamese Army forces were limited and thus unable to be everywhere at once, the North Vietnamese could readily achieve a build-up in the north. Like the periodic massing against outposts, the build-up pulled U.S. forces away from conducting search and destroy operations and from securing villages. Keeping American forces away from the villages adversely affected pacification, a program that had to succeed if the insurgency ever was to be suppressed.
Communist political cadres composed of an estimated 40,000 men, backed by regular and local units, secretly controlled vast numbers of communities outside the cities by means ranging from propaganda and cajolery to intimidation and murder. This Viet Cong shadow government exacted taxes, drafted young men for its military ranks, and bent the population to its ends. Its grip had to be broken in order to deprive the guerrillas of sustenance and base support.
The history of pacification was often a history of frustration and failure. Because of inadequate resources, lack of peasant support, and political problems, several programs under President Diem had failed. After Diem, a new program oriented more toward economic assistance also foundered in the face of political instability, growing insecurity in the countryside, and the defeats the Viet Cong had inflicted on the South Vietnamese Army.
At the beginning of 1966 a new program called Revolutionary Development seemed promising. At the core of the program were teams of fifty-nine specially trained South Vietnamese. Moving into a hamlet, a team worked to identify and eliminate the secret political cadre of Viet Cong, remove corrupt South Vietnamese officials from office, organize democratic institutions, and create a hamlet defense force. These objectives accomplished, the team moved on to the next hamlet, leaving the first to the South Vietnamese government agencies to develop programs in education, health, land reform, and financial credit. Supplementing these teams, U.S. civilian agencies worked at various levels in information, agriculture, and public health programs.
Organizational responsibility for the support of pacification shifted in early 1966 from several competing U.S. government agencies to the Deputy U.S. Ambassador. The civilian programs were further unified later in the year under a U.S. Embassy Office of Civil Operations, which had a military counterpart in the Revolutionary Development Support Directorate of the Military Assistance Command, Vietnam. In search of further co-ordination, President Johnson in May 1967 gave full responsibility for pacification support to the Military Assistance Command, fusing the Office of Civil Operations and the Revolutionary Development Support Directorate in a unique civil-military amalgam known as CORDS, an acronym for its components. A civilian with the rank of ambassador was assigned to head the program.
Through CORDS the U.S. Army's role in pacification went far beyond civic action. Army officers or their civilian colleagues gave pacification advice and support to the Vietnamese on a wide range of subjects, including local security and village elections. The purpose of the new pacification program was sustained local security with unprecedented attention given to improving and augmenting the Vietnamese militia. CORDS also initiated a program, later known as PHOENIX, to eliminate the secret Viet Cong political organization in South Vietnam. Although CORDS pursued an aggressive policy and U.S. forces often provided such assistance as digging wells, building schools, and furnishing medical aid, pacification focused on getting the Vietnamese themselves to do the job. In the long run the success or failure of pacification would depend upon the ability of the South Vietnamese government to protect the people and enlist their support.
The Thieu-Ky government moved closer to the people in the fall of 1966 by calling an election for a constituent assembly. Despite disruptive efforts of the Viet Cong, the electorate turned out in impressive numbers. Hamlet and village elections and then national assembly and presidential elections, the last for a four-year term, followed the next year. One of several candidates, Thieu failed to gain a majority of the vote, but he achieved a clear plurality to provide his government with at least a measure of popular support.
The Military Campaign In 1967
In response to the North Vietnamese build-up along the demilitarized zone in early 1967, General Westmoreland sent the first major U.S. Army units into the southern portion of the I Corps zone, thereby freeing U.S. Marine Corps units to move farther north. Among the Army units eventually committed were the 11th, 196th, and 198th Infantry Brigades, which subsequently constituted a new division, the 23d (Americal), the parenthetical designation dating back to a division that had been organized during World War II on New Caledonia.
In the Central Highlands, alert intelligence and quick U.S. action thwarted enemy attempts during the summer of 1967 to converge against the Special Forces camps. At the same time in the provinces near Saigon, the campaign continued against the Viet Cong base areas.
Early in the year, in an operation called Cedar Falls, U.S. and South Vietnamese Army forces in the equivalent of more than two divisions sealed off the Iron Triangle and systematically swept that tangle of woods, caves, and bunkers north of Saigon; but the enemy returned to his hideouts once U.S. and South Vietnamese troops had departed. After a second sweep a few weeks later, U.S. engineers leveled much of the area with Rome plows.
In late February, many of these same units, including the 173d Airborne Brigade, which made the only U.S. combat parachute jump of the war, participated in Operation Junction City, a large offensive employing four South Vietnamese and twenty-two U.S. combat battalions. While some units formed a giant horseshoe cordon around War Zone C, cavalry and mechanized forces swept up the open end of the horseshoe. Because of the proximity of the Cambodian border, many of the enemy escaped, but over a period of three months, more than 2,700 were killed. Vast numbers of fortifications, headquarters complexes, and other installations were destroyed, and intelligence documents, equipment, and tons of supplies were either captured or destroyed.
The ratio of enemy to U.S. troops killed was in most cases disproportionately high for the enemy. In U.S. search and destroy operations, a ratio of 10 Viet Cong to I American was common, and in enemy assaults against prepared U.S. positions, the ratio was higher. In one two-day assault against a fire support base in War Zone C, for example, 609 Viet Cong died as against 10 Americans.
With completion early in 1967 of the Dong Tam base among the rice paddies of the Mekong Delta, a brigade of the 9th Infantry Division initiated the first U.S. operations in the IV Corps zone, a region crisscrossed by canals and rivers. Employing barracks ships, U.S. Navy armored troop carriers and fire support boats, and artillery mounted on barges, this brigade extended fighting to the delta and its inland waterways. One of the first operations was against a heretofore sacrosanct base called the Cam Son Secret Zone. By the end of the year, the Mobile Riverine Force had killed approximately 1,500 Viet Cong.
For all the success of U.S. and South Vietnamese Army operations and the large numbers of Viet Cong and North Vietnamese killed, there were indications in the fall of 1967 of another enemy build-up, particularly in areas close to Communist havens in Laos and Cambodia. In late October the Viet Cong struck again at the Special Forces camp at Loc Ninh, but intensive air and artillery support and quick arrival of American and South Vietnamese reinforcements saved the camp. The enemy nevertheless continued to give battle. He finally left the field ten days later after losing 800 dead and killing 50 men from U.S. and South Vietnamese Army units. Success was in no small part attributable to a preponderance of U.S. firepower-30,000 rounds of artillery fire, 450 close support air sorties, and 8 bombardments by B-52's.
At the same time, the Communists again increased their strength in the Central Highlands, concentrating some 12,000 men around a Special Forces camp at Dak To, in the northern part of Kontum Province where the borders of Laos, Cambodia, and South Vietnam meet. As the enemy probed, U.S. and South Vietnamese reinforcements brought a total commitment to the defense of sixteen battalions. After repulsing a Communist assault, American and South Vietnamese units moved out from their fire support bases to dislodge an enemy apparently determined to hold in surrounding hills. In the ensuing fight, the Communists lost 1,400 dead in the largest and most costly fight in the highlands since the Ia Drang valley campaign two years before.
The enemy resurgence there and at Loc Ninh and another heavy concentration in the vicinity of a Marine base at Khe Sanh, in the northwestern corner of the country, were disturbing to U.S. commanders. There was also disquieting evidence that the enemy was planning an offensive to begin with the lunar new year holiday (Tet) in early 1968, but there was no clue to its magnitude.
The Tet Offensive-1968
As the date for the offensive neared, the Communists shifted supplies to concealed sites close to the towns and cities, while with the help of sympathizers among the population, soldiers in civilian dress mingled with the holiday crowds to infiltrate the densely populated areas. The offensive appears to have had two objectives: to foster antigovernment uprisings among the South Vietnamese population and to further antiwar sentiment in the United States. Some captured enemy documents indicated that the Communists intended the offensive to lead to total victory.
The assaults began in the northern and central provinces before daylight on 30 January and in the Saigon and Mekong Delta regions that night. Some 84,000 Viet Cong and North Vietnamese attacked 36 of 43 provincial capitals, 5 of 6 autonomous cities, 34 of 242 district capitals, and at least 50 hamlets. Never before had the enemy mounted such a concentrated effort.
The Communists penetrated in strength into ten cities, including Saigon and Hue; but even though many South Vietnamese troops were away from their posts on leave, the South Vietnamese police, militia, and soldiers repulsed the attacks in four cities in a matter of hours. Fighting lasted for up to three days in four others, while in Saigon and Hue the battle was protracted.
The attack in Saigon began with a sapper assault against the U.S. Embassy. Other assaults were directed against the Presidential Palace, the compound of the Vietnamese Joint General Staff, and nearby Tan Son Nhut air base, but the only successes were brief incursions into the compound and into the fringes of Tan Son Nhut. Considerable fighting remained, nevertheless, before American and South Vietnamese troops cleared all the enemy from some sections of Saigon.
In Hue, a low fog facilitated infiltration of 8 enemy battalions, which gained control of most of the city, including the ancient Citadel, a walled enclave encompassing historic buildings of the imperial court. Involving at times 3 U.S. Marine Corps, 3 U.S. Army, and II South Vietnamese battalions, the fight to recapture Hue lasted for almost a month.
Apparently in co-ordination with the offensive, heavy fighting occurred in two remote regions: around the Special Forces camp at Dak To in the Central Highlands and around the U.S. Marine Corps base at Khe Sanh. Detected while on the move, a North Vietnamese division near Dak To was systematically battered by U.S. Air Force planes, the 4th Infantry Division, and a South Vietnamese regiment, while at Khe Sanh a prolonged battle developed between U.S. marines and at least two North Vietnamese divisions. Against every enemy effort to dislodge them the marines and a battalion of South Vietnamese Rangers held fast, while artillery, including 16 U.S. Army 175-mm. pieces, and air power, including B-52 bombers in a close support role, inflicted heavy casualties. As the North Vietnamese began to fade away in the face of such awesome firepower, a Marine regiment and contingents of the 1st Cavalry Division in early April re-established ground contact with Khe Sanh. With the arrival of more U.S. Army troops to reinforce the marines in the northern provinces-including the 101st Airborne Division, converted to an airmobile unit; a mechanized brigade; and a new headquarters, the XXIV Corps-Khe Sanh was abandoned in favor of mobile defensive tactics.
As in other instances in recent military history-such as the German offensive at Chemin des Dames in 1918 and in the Ardennes in 1944 and the Chinese Communist intervention in Korea in 1950-the sudden enemy offensive, following close upon optimistic reports from the field, shocked the American public and spurred demands by many for a pull-out from Vietnam. The Tet offensive thus was an apparent psychological victory for the enemy. Yet it was at the same time a military defeat. It failed to engender either an uprising or appreciable support among the South Vietnamese. Indeed, the determination of both South Vietnamese units and the populace appeared to increase. In the Tet offensive, the Communists lost 6,000 captured and 32,000 killed as against U.S. and South Vietnamese losses of just over 2,000 each. Three times during the next six months the enemy tried to mount new offensives, but in most cases these degenerated into sporadic mortar and rocket attacks. By coming into the open, the enemy had exposed himself to massive American firepower and in the first nine months of 1968 lost 137,000 men killed.
The heavy losses may have had something to do with the Communists' agreement in May to open negotiations aimed at ending the war, although their acceptance ostensibly came as a result of a decision by President Johnson at the end of March to halt the bombing of North Vietnam north of the 19th parallel. Early hopes that the discussions, held in Paris, might lead to peace were soon dispelled. Although the President tried to spur the negotiations by halting all bombing of North Vietnam in November, the talks remained largely sterile.
The Tet offensive appeared at first to have dealt a severe setback to the pacification program. It was true that many local defense units and Revolutionary Development teams had abandoned the countryside to take refuge in the cities, but the enemy had incurred too many losses to take advantage of it before the South Vietnamese forces returned. In the fall of 1968, the South Vietnamese government with major U.S. support launched an Accelerated Pacification Campaign that brought new vitality to pacification. Local militia advised by special teams of U.S. Army combat veterans strengthened security. Government influence expanded into widespread areas of the countryside previously dominated by the Viet Cong to such an extent that two years later at least some measure of government control was evident in all but a few remote regions.
Invasions Of Cambodia And Laos
Following the enemy's 1968 offensive, the level of combat through much of the country dropped perceptibly. General Creighton W. Abrams, who succeeded General Westmoreland in mid-1968 as the head of the Military Assistance Command, Vietnam, was able to scale down the size of the forces he sent into the field searching for the foe. General Abrams was also able to afford the forces for a sustained campaign in the A Shau valley, a rugged stretch of mountainous country along the Laotian border that heretofore had been almost the sole province of the enemy.
The enemy's heavy losses strengthened the prospect of South Vietnam's assuming the entire combat role and eventually the support and logistical assignments as well. That the South Vietnamese armed and paramilitary forces had increased to a million men further encouraged the possibility. A concerted effort to supply all South Vietnamese units, including paramilitary forces, with modern weapons and equipment began. Called "Vietnamization," the program was to allow American units to begin a phased withdrawal from the country. President Nixon on 8 June 1969 announced the first of a series of withdrawals.
With the emergence in Cambodia of an anti-Communist government replacing an ostensibly neutral regime, President Nixon relaxed the restriction on moving against the enemy bases inside Cambodia. On 29 April 1970 South Vietnamese Army troops entered the "Parrot's Beak" section of Cambodia, which extends into South Vietnamese territory to within thirty miles of Saigon. Three days later American and South Vietnamese troops entered the "Fish Hook," another promontory farther north. Other South Vietnamese troops subsequently moved up the Mekong River corridor in the direction of the Cambodian capital of Phnom Penh, while the Cambodian Army denied Communist use of the port of Sihanoukville. All together, 31,000 U.S. troops and 43,000 South Vietnamese entered Cambodia. President Nixon limited the depth of the penetration by American troops to twenty-one miles and specified that all U.S. forces would be out of Cambodia within sixty days. The last withdrew on 29 June.
Although many of the Communist troops fled from their Cambodia bases, the enemy still lost more than 11,000 killed. American losses were 337 killed. The important result was the denial of Sihanoukville to the enemy and elimination of the sanctuaries, the impact of which was soon manifest in a further reduction in enemy activity in the III and IV Corps zones.
The only route for supplies and reinforcement left to the North Vietnamese was the Ho Chi Minh Trail, already subject to air attacks. On 8 February 1971 the vanguard of 21,000 South Vietnamese troops entered Laos to disrupt the trail complex. Temporarily reactivating the base at Khe Sanh, the U.S. furnished air, artillery, and logistical support, although no U.S. ground combat units operated in Laos. The North Vietnamese fought with determination, inflicting sharp losses on four of twelve South Vietnamese battalions, but in turn taking severe losses themselves. The heaviest concentration of antiaircraft fire yet encountered destroyed eighty-nine American helicopters. Near the end of March, the South Vietnamese withdrew. Despite the fierce fighting, an encouraging aspect of both the Cambodian and Laotian operations was the improved performance and morale of the South Vietnamese Army.
Toward the end of the seventh year of large-scale U.S. involvement in Vietnam, almost all major U.S. Army combat units had returned to the United States, and American troop strength in Vietnam was down below 200,000 with indications of continuing withdrawals. It had been one of the nation's costliest wars: more than 45,000 men were killed in combat (30,200 of them soldiers) and almost 10,000 died from other causes. Approximately 150,000 were wounded seriously enough to require hospital care, of whom two-thirds were soldiers. Enemy losses were impossible to determine with certainty, but the North Vietnamese at one point admitted the loss of over half a million men.
In Vietnam, the United States Army fought a war of contrasts. On the one hand, the war was more sophisticated than any in history, introducing not only complex weapons and equipment but also, with the helicopter, a third dimension that the airborne attacks of World War II and Korea had only foreshadowed. On the other hand, there was a return to the primitive, often pitting man against man in a conflict and an environment where wile and stamina might determine who would prevail. In a way it was two wars, a military campaign involving a compendium of all the Army had learned from the Revolution through Korea and at the same time a vast civic action project, using the men and tools of war in the task of winning the confidence and support of a people. For the United States Vietnam was a limited war in the classic sense of the American Revolution, the War of 1812, the Indian wars, the wars with Mexico and Spain, and Korea. In the same way that history cannot prophesy, only illuminate, this war of contrasts produced no clear pattern for the warfare of the future.