The Vietnam Conflict and Vietnam War

The Vietnam Conflict and Vietnam War were two Cold War-era military conflicts that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to XXthe fall of Saigon on 30 April 1975XX. The conflict and war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of South Vietnam, supported by the United States and other anti-communist countries. The Viet Cong (also known as the National Liberation Front, or NLF), a lightly armed South Vietnamese communist-controlled common front, largely fought a guerrilla war against anti-communist forces in the region. The Vietnam People's Army (North Vietnamese Army) engaged in a more conventional war, at times committing large units into battle. U.S. and South Vietnamese forces relied on air superiority and overwhelming firepower to conduct search and destroy operations, involving ground forces, artillery, and airstrikes.

The U.S. government viewed involvement in the war as a way to prevent a communist takeover of South Vietnam as part of their wider strategy of containment. The North Vietnamese government and Viet Cong viewed the conflict as a colonial war, fought initially against France, backed by the U.S., and later against South Vietnam, which it regarded as a U.S. puppet state. American military advisors arrived in what was then French Indochina beginning in 1950. U.S. involvement escalated in the early 1960s, with troop levels tripling in 1961 and tripling again in 1962. U.S. combat units were deployed beginning in 1965. Operations spanned international borders, with Laos and Cambodia heavily bombed. American involvement in the war peaked in 1968, at the time of the Tet Offensive. After this, U.S. ground forces were gradually withdrawn as part of a policy known asVietnamization. XXDespite the Paris Peace Accords, signed by all parties in January 1973, fighting continued.XX

XXU.S. military involvement ended on 15 August 1973 as a result of the Case–Church Amendment passed by the U.S. Congress. The capture of Saigon by the Vietnam People's Army in April 1975 marked the end of the war, and North and South Vietnam were reunified the following year. The war exacted a huge human cost in terms of fatalities (see Vietnam War casualties). Estimates of the number of Vietnamese soldiers and civilians killed vary from less than one million to more than five million. Some 200,000–300,000 Cambodians, 20,000–200,000 Laotians, and 58,220 U.S. service members also died in the conflict.XX

Background to 1949
France began its conquest of Indochina in the late 1850s, and completed pacification by 1893. The Treaty of Huế, concluded in 1884, formed the basis for French colonial rule in Vietnam for the next seven decades. In spite of military resistance, most notable by the Can Vuong of Phan Dinh Phung, by 1888 the area of the current-day nations of Cambodia and Vietnam was made into the colony of French Indochina (Laos was added later). Various Vietnamese opposition movements to French rule existed during this period, such as the Viet Nam Quoc Dan Dang who staged the failed Yen Bai mutiny in 1930, but none were ultimately as successful as the Viet Minh common front, which was founded in 1941, controlled by the Indochinese Communist Party, and funded by the U.S. and the Chinese Nationalist Party in its fight against Japanese occupation.

During World War II, the French were defeated by the Germans in 1940. For French Indochina, this meant that the colonial authorities became Vichy French, allies of the German-Italian Axis powers. In turn this meant that the French collaborated with the Japanese forces after their invasion of French Indochina during 1940. The French continued to run affairs in the colony, but ultimate power resided in the hands of the Japanese.

The Viet Minh was founded as a league for independence from France, but also opposed Japanese occupation in 1945 for the same reason. The U.S. and Chinese Nationalist Party supported them in the fight against the Japanese. However, they did not have enough power to fight actual battles at first. Viet Minh leader Ho Chi Minh was suspected of being a communist and jailed for a year by the Chinese Nationalist Party.

Double occupation by France and Japan continued until the German forces were expelled from France and the French Indochina colonial authorities started holding secret talks with the Free French. Fearing that they could no longer trust the French authorities, the Japanese army interned them all on 9 March 1945 and assumed direct control themselves through their puppet state, the Empire of Vietnam, under Bảo Đại.

During 1944–1945, a deep famine struck northern Vietnam due to a combination of bad weather and French/Japanese exploitation. 1 million people died of starvation (out of a population of 10 million in the affected area). Exploiting the administrative gap that the internment of the French had created, the Viet Minh in March 1945 urged the population to ransack rice warehouses and refuse to pay their taxes. Between 75 and 100 warehouses were consequently raided. This rebellion against the effects of the famine and the authorities that were partially responsible for it bolstered the Viet Minh's popularity and they recruited many members during this period.

In August 1945, the Japanese had been defeated and surrendered unconditionally. In French Indochina this created a power vacuum, as the French were still interned and the Japanese forces stood down. The Viet Minh stepped into this vacuum and grasped power across Vietnam in the August Revolution, largely supported by the Vietnamese population. After their defeat in the war, the Imperial Japanese Army (IJA) gave weapons to the Vietnamese, and kept Vichy French officials and military officers imprisoned for a month after the surrender. The Việt Minh had recruited more than 600 Japanese soldiers and given them roles to train or command Vietnamese soldiers.

Ho Chi Minh declared the independent Democratic Republic of Vietnam before a crowd of 500,000 in Hanoi on 2 September 1945. In an overture to the Americans, he began his speech by paraphrasing the United States Declaration of Independence: ''All men are created equal. The Creator has given us certain inviolable Rights: the right to Life, the right to be Free, and the right to achieve Happiness.''

However, the major allied victors of World War II, the United Kingdom, the United States, and the Soviet Union, all agreed the area belonged to the French. As the French did not have the ships, weapons, or soldiers to immediately retake Vietnam, the major powers came to an agreement that British troops would occupy the south while Nationalist Chinese forces would move in from the north. Nationalist Chinese troops entered the country to disarm Japanese troops north of the 16th parallel on 14 September 1945. When the British landed in the south, they rearmed the interned French forces as well as parts of the surrendered Japanese forces to aid them in retaking southern Vietnam, as they did not have enough troops to do this themselves.

Following the party line from Moscow, Ho Chi Minh initially attempted to negotiate with the French, who were slowly re-establishing their control across the country. In January 1946, the Viet Minh won elections across central and northern Vietnam. On 6 March 1946, Ho signed an agreement allowing French forces to replace Nationalist Chinese forces, in exchange for French recognition of the Democratic Republic of Vietnam as a "free" republic within the French Union, with the specifics of such recognition to be determined by future negotiation. The French landed in Hanoi by March 1946 and in November of that year they ousted the Viet Minh from the city. British forces departed on 26 March 1946, leaving Vietnam in the hands of the French. Soon thereafter, the Viet Minh began a guerrilla war against the French Union forces, beginning the First Indochina War.

The war spread to Laos and Cambodia, where Communists organized the Pathet Lao and the Khmer Serei, both of which were modeled on the Viet Minh. Globally, the Cold War began in earnest, which meant that the rapprochement that existed between the Western powers and the Soviet Union during World War II disintegrated. The Viet Minh fight was hampered by a lack of weapons; this situation changed by 1949 when the Chinese Communists had largely won the Chinese Civil War and were free to provide arms to their Vietnamese allies.

Exit of the French, 1950–1954
In January 1950, the communist nations, led by the People's Republic of China (PRC), recognized the Viet Minh's Democratic Republic of Vietnam, based in Hanoi, as the government of Vietnam, while non-communist nations recognized the French-backed State of Vietnam in Saigon, led by former Emperor Bảo Đại, as the Vietnamese government the following month. The outbreak of the Korean War in June 1950 convinced many Washington policymakers that the war in Indochina was an example of communist expansionism directed by the Kremlin. PRC military advisors began assisting the Viet Minh in July 1950. PRC weapons, expertise, and laborers transformed the Viet Minh from a guerrilla force into a regular army. In September 1950, the United States created a Military Assistance and Advisory Group (MAAG) to screen French requests for aid, advise on strategy, and train Vietnamese soldiers. By 1954, the United States had supplied 300,000 small arms and spent US$1 billion in support of the French military effort, shouldering 80 percent of the cost of the war.

There were also talks between the French and Americans in which the possible use of three tactical nuclear weapons was considered, though reports of how seriously this was considered and by whom are even now vague and contradictory. One version of the plan for the proposed Operation Vulture envisioned sending 60 B-29s from U.S. bases in the region, supported by as many as 150 fighters launched from U.S. Seventh Fleet carriers, to bomb Viet Minh commander Vo Nguyen Giap's positions. The plan included an option to use up to three atomic weapons on the Viet Minh positions. Admiral Arthur W. Radford, Chairman of the U.S. Joint Chiefs of Staff, gave this nuclear option his backing. U.S. B-29s, B-36s, and B-47s could have executed a nuclear strike, as could carrier aircraft from the Seventh Fleet.

U.S. carriers sailed to the Gulf of Tonkin, and reconnaissance flights over Dien Bien Phu were conducted during the negotiations. According to U.S. Vice-President Richard Nixon, the plan involved the Joint Chiefs of Staff drawing up plans to use three small tactical nuclear weapons in support of the French. Nixon, a so-called "hawk" on Vietnam, suggested that the United States might have to "put American boys in". U.S. President Dwight D. Eisenhower made American participation contingent on British support, but London was opposed to such a venture. In the end, convinced that the political risks outweighed the possible benefits, Eisenhower decided against the intervention. As an experienced five-star general, Eisenhower was very wary of getting the United States involved in a land war in Asia.

The Viet Minh received crucial support from the Soviet Union and PRC. PRC support in the Border Campaign of 1950 allowed supplies to come from the PRC into Vietnam. Throughout the conflict, U.S. intelligence estimates remained skeptical of French chances of success.

The Battle of Dien Bien Phu marked the end of French involvement in Indochina. Giap's Viet Minh forces handed the French a stunning military defeat, and on 7 May 1954, the French Union garrison surrendered. Of the 12,000 French prisoners taken by the Viet Minh, only 3,000 survived. At the Geneva Conference, the French negotiated a ceasefire agreement with the Viet Minh, and independence was granted to Cambodia, Laos, and Vietnam.

Transition period
Vietnam was temporarily partitioned at the 17th parallel, and under the terms of the Geneva Accords, civilians were to be given the opportunity to move freely between the two provisional states for a 300-day period. Elections throughout the country were to be held in 1956 to establish a unified government. Around one million northerners, mainly minority Catholics, fled south, fearing persecution by the communists following an American propaganda campaign using slogans such as "The Virgin Mary is heading south", and aided by a U.S. funded $93 million relocation program, which included ferrying refugees with the Seventh Fleet. It is estimated that as many as two million more would have left had they not been stopped by the Viet Minh. The northern, mainly Catholic refugees were meant to give the later Ngô Đình Diệm regime a strong anti-communist constituency. Diem later went on to staff his administration's key posts mostly with northern and central Catholics.

In addition to the Catholics flowing south, up to 130,000 "Revolutionary Regroupees" went to the north for "regroupment," expecting to return to the south within two years. The Viet Minh left roughly 5,000 to 10,000 cadres in the south as a "politico-military substructure within the object of its irredentism." The last French soldiers were to leave Vietnam in April 1956. The PRC completed its withdrawal from North Vietnam at around the same time. Around 52,000 Vietnamese civilians moved from south to north.

In the north, the Viet Minh ruled as the Democratic Republic of Vietnam and engaged in a drastic land reform program in which more than 100,000 perceived "class enemies" were executed. In 1956, leaders in Hanoi admitted to "excesses" in implementing this program and restored a large amount of the land to the original owners.

The south, meanwhile, constituted the State of Vietnam, with Bảo Đại as Emperor and Ngô Đình Diệm (appointed in July 1954) as his prime minister. In June 1955, Diem announced that the scheduled 1956 elections would not be held, claiming South Vietnam had rejected the Geneva Accords from the beginning and was therefore not bound by them. "How can we expect 'free elections' to be held in the Communist North?" he asked. President Eisenhower echoed senior U.S. experts when he wrote that, in 1954, "80 per cent of the population would have voted for the Communist Ho Chi Minh" over Emperor Bảo Đại.

From April to June 1955, Diem (against U.S. advice) eliminated any political opposition in the south by launching military operations against the Cao Dai religious sect, the Hoa Hao sect of Ba Cut, and the Binh Xuyen organized crime group (which was allied with members of the secret police and some military elements). As broad-based opposition to his harsh tactics mounted, Diem increasingly sought to blame the communists.

In a referendum on the future of the State of Vietnam on 23 October 1955, Diem rigged the poll supervised by his brother Ngo Dinh Nhu and was credited with 98.2 percent of the vote, including 133% in Saigon. His American advisers had recommended a more modest winning margin of "60 to 70 percent." Diem, however, viewed the election as a test of authority. Three days later, he declared South Vietnam to be an independent state known as the Republic of Vietnam (ROV), with himself as president.

The ROV was created largely because of the Eisenhower administration's desire for an anti-communist state in the region. The domino theory, which argued that if one country fell to communism, then all of the surrounding countries would follow, was first proposed as policy by the Eisenhower administration. It was, and is still, commonly hypothesized that it applied to Vietnam. John F. Kennedy, then a U.S. Senator, said in a speech to the American Friends of Vietnam: "Burma, Thailand, India, Japan, the Philippines and obviously Laos and Cambodia are among those whose security would be threatened if the Red Tide of Communism overflowed into Vietnam."

Diem era, 1955–1963
A devout Roman Catholic, Diem was fervently anti-communist, nationalist, and socially conservative. Historian Luu Doan Huynh notes that "Diem represented narrow and extremist nationalism coupled with autocracy and nepotism." As he was a wealthy Catholic, many ordinary Vietnamese viewed Diem as part of the elite who had helped the French rule Vietnam; Diem had been interior minister in the colonial government. The majority of Vietnamese people were Buddhist, and were alarmed by actions such as Diem's dedication of the country to the Virgin Mary.

Beginning in the summer of 1955, Diem launched the "Denounce the Communists" campaign, during which communists and other anti-government elements were arrested, imprisoned, tortured, or executed. He instituted the death penalty against any activity deemed communist in August 1956. The regime branded its opponents Viet Cong ("Vietnamese communist") to degrade their nationalist credentials. As a measure of the level of political repression, about 12,000 suspected opponents of Diem were killed between 1955 and 1957 and by the end of 1958 an estimated 40,000 political prisoners had been jailed.

In May 1957, Diem undertook a ten-day state visit to the United States. President Eisenhower pledged his continued support, and a parade was held in Diem's honor in New York City. Although Diem was publicly praised, in private Secretary of State John Foster Dulles conceded that Diem had been selected because there were no better alternatives.

Future U.S. Secretary of Defense Robert McNamara wrote that the new American patrons of the ROV were almost completely ignorant of Vietnamese culture. They knew little of the language or long history of the country. There was a tendency to assign American motives to Vietnamese actions, and Diem warned that it was an illusion to believe that blindly copying Western methods would solve Vietnamese problems.

Insurgency in the South, 1954–1960
President Eisenhower noted that had the Geneva Accords been held, "possibly 80 percent of the population would have voted for Communist Ho Chi Minh" and the government quickly became more repressive and unpopular. The Diem government had largely failed in implementing a land reform program for the peasants of South Vietnam (90% of the population) which along with "Peace, security, freedom, [and] their standard of living" was the peasants' prime concern according to specialist Philippe Devillers. Among the changes the government altered the tenant structure to competitive bidding which led to more tenant insecurity. Only 10% of the tenants benefited from the program and were oftentimes northerners, refugees, or Catholics which created more animosity among the Vietnamese. In 1959 the program became inoperative and by 1960, only 2% of the landowners owned 45% of the land.

The South government used widespread repression, between 1954 and 1960 it captured 50,000 prisoners and had put them into "political reeducation camps" as part of the Denunciation of Communists Campaign. In 1959 British specialist PJ Honey was invited to examine the camps and concluded after interviewing rural Vietnamese that "the consensus of the opinion expressed by these peoples is that...the majority of the detainees are neither communists nor pro-communists."

XXAccording to the Pentagon Papers the prisons were "little more than concentration camps for potential foes of the government" and used torture regardless of whether they were communist or not.XX The Diem government had also abolished elections for village councils out of fear of large amounts of Viet Minh candidates winning and replaced administrative village autonomy with government officials.

This had an effect, between 1954 and 1957 there was large scale random dissidence in the countryside which the Diem government managed to successfully quell. In early 1957 South Vietnam had its first peace in over a decade. However, by mid-1957 through 1959 incidents of violence increased but the government "did not construe it as a campaign, considering the disorders too diffuse to warrant committing major GVN resources." By Early 1959 however, Diem had considered it a campaign and implemented Law 10/59, which made political violence punishable by death and property confiscation. There had been some division among former Viet Minh whose main goal was to hold the elections promised in the Geneva Accords, leading to "wildcat" activities separate from the other communists and anti-GVN activists.

XXIn December 1960, the National Liberation Front (NLF) was formally created consisting of all anti-GVN activists and included non-communists. XXAccording to the Pentagon Papers, the NLF "placed heavy emphasis on the withdrawal of American advisors and influence, on land reform and liberalization of the GVN, on coalition government and the neutralization of Vietnam."XX Often the leaders of the organization were kept secret.

North Vietnam interference?
Very little evidence points to organization or interference on the part of North Vietnam. XXAs the Pentagon Papers point out, "No direct links have been established between Hanoi and perpetrators of rural violence."XX As Kahin and Lewis point out:XX

Contrary to United States policy assumptions, all available evidence shows that the revival of the civil war in the South in 1958 was undertaken by Southerners at their own—not Hanoi's—initiative...Insurgency activity against the Saigon government began in the South under Southern leadership not as a consequence of any dictate from Hanoi, but contrary to Hanoi's injunctions.

Similarly, historian Arthur Schlesinger Jr. states that "it was not until September, 1960 that the Communist Party of North Vietnam bestowed its formal blessing and called for the liberation of the south from American imperialism".

During John F. Kennedy's administration, 1961–1963
In the 1960 U.S. presidential election, Senator John F. Kennedy defeated Vice-President Richard Nixon. Although Eisenhower warned Kennedy about Laos and Vietnam, Europe and Latin America "loomed larger than Asia on his sights." In his inaugural address, Kennedy made the ambitious pledge to "pay any price, bear any burden, meet any hardship, support any friend, oppose any foe, in order to assure the survival and success of liberty." In June 1961, he bitterly disagreed with Soviet premier Nikita Khrushchev when they met in Vienna to discuss key U.S.-Soviet issues.

The Kennedy administration remained essentially committed to the Cold War foreign policy inherited from the Truman and Eisenhower administrations. In 1961, the U.S. had 50,000 troops based in Korea, and Kennedy faced a three-part crisis – the failure of the Bay of Pigs Invasion, the construction of the Berlin Wall, and a negotiated settlement between the pro-Western government of Laos and the Pathet Lao communist movement. These made Kennedy believe that another failure on the part of the United States to gain control and stop communist expansion would fatally damage U.S. credibility with its allies and his own reputation. Kennedy was thus determined to "draw a line in the sand" and prevent a communist victory in Vietnam. He told James Reston of The New York Times immediately after his Vienna meeting with Khrushchev, "Now we have a problem making our power credible and Vietnam looks like the place."

In May 1961, Vice President Lyndon B. Johnson visited Saigon and enthusiastically declared Diem the "Winston Churchill of Asia." Asked why he had made the comment, Johnson replied, "Diem's the only boy we got out there." Johnson assured Diem of more aid in molding a fighting force that could resist the communists.

Kennedy's policy toward South Vietnam rested on the assumption that Diem and his forces must ultimately defeat the guerrillas on their own. He was against the deployment of American combat troops and observed that "to introduce U.S. forces in large numbers there today, while it might have an initially favorable military impact, would almost certainly lead to adverse political and, in the long run, adverse military consequences." The quality of the South Vietnamese military, however, remained poor. Bad leadership, corruption, and political promotions all played a part in emasculating the ARVN. The frequency of guerrilla attacks rose as the insurgency gathered steam. While Hanoi's support for the NLF played a role, South Vietnamese governmental incompetence was at the core of the crisis. One major issue Kennedy raised was whether the Soviet space and missile programs had surpassed those of the United States. Although Kennedy stressed long-range missile parity with the Soviets, he was also interested in using special forces for counterinsurgency warfare in Third World countries threatened by communist insurgencies. Although they were originally intended for use behind front lines after a conventional invasion of Europe, Kennedy believed that the guerrilla tactics employed by special forces such as the Green Berets would be effective in a "brush fire" war in Vietnam.

Kennedy advisers Maxwell Taylor and Walt Rostow recommended that U.S. troops be sent to South Vietnam disguised as flood relief workers. Kennedy rejected the idea but increased military assistance yet again. In April 1962, John Kenneth Galbraith warned Kennedy of the "danger we shall replace the French as a colonial force in the area and bleed as the French did." By 1963, there were 16,000 American military personnel in South Vietnam, up from Eisenhower's 900 advisors.

The Strategic Hamlet Program had been initiated in 1961. This joint U.S.-South Vietnamese program attempted to resettle the rural population into fortified camps. The aim was to isolate the population from the insurgents, provide education and health care, and strengthen the government's hold over the countryside. The Strategic Hamlets, however, were quickly infiltrated by the guerrillas. The peasants resented being uprooted from their ancestral villages. In part, this was because Colonel Pham Ngoc Thao, a Diem favourite who was instrumental in running the program, was in fact a communist agent who used his Catholicism to gain influential posts and damage the ROV from the inside.

The government refused to undertake land reform, which left farmers paying high rents to a few wealthy landlords. Corruption dogged the program and intensified opposition.

On 23 July 1962, fourteen nations, including the People's Republic of China, South Vietnam, the Soviet Union, North Vietnam and the United States, signed an agreement promising the neutrality of Laos.

Coup and assassinations
The inept performance of the South Vietnamese army was exemplified by failed actions such as the Battle of Ap Bac on 2 January 1963, in which a small band of Viet Cong beat off a much larger and better equipped South Vietnamese force, many of whose officers seemed reluctant even to engage in combat. The ARVN were led in that battle by Diem's most trusted general, Huynh Van Cao, commander of the IV Corps. Cao was a Catholic who had been promoted due to religion and fidelity rather than skill, and his main job was to preserve his forces to stave off coups; he had earlier vomited during a communist attack. Some policymakers in Washington began to conclude that Diem was incapable of defeating the communists and might even make a deal with Ho Chi Minh. He seemed concerned only with fending off coups, and had become more paranoid after attempts in 1960 and 1962, which he partly attributed to U.S. encouragement. As Robert F. Kennedy noted, "Diem wouldn't make even the slightest concessions. He was difficult to reason with..."

Discontent with Diem's policies exploded following the Huế Phật Đản shootings of majority Buddhists who were protesting against the ban on the Buddhist flag on Vesak, the Buddha's birthday. This resulted in mass protests against discriminatory policies that gave privileges to the Catholic Church and its adherents. Diem's elder brother Ngo Dinh Thuc was the Archbishop of Huế and aggressively blurred the separation between church and state. Thuc's anniversary celebrations shortly before Vesak had been bankrolled by the government and Vatican flags were displayed prominently. There had also been reports of Buddhist pagodas being demolished by Catholic paramilitaries throughout Diem's rule. Diem refused to make concessions to the Buddhist majority or take responsibility for the deaths. On 21 August 1963, the ARVN Special Forces of Colonel Le Quang Tung, loyal to Diem's younger brother Ngo Dinh Nhu, raided pagodas across Vietnam, causing widespread damage and destruction and leaving a death toll estimated to range into the hundreds. U.S. officials began discussing the possibility of a regime change during the middle of 1963. The United States Department of State was generally in favor of encouraging a coup, while the Defense Department favored Diem. Chief among the proposed changes was the removal of Diem's younger brother Nhu, who controlled the secret police and special forces was seen as the man behind the Buddhist repression and more generally the architect of the Ngo family's rule. This proposal was conveyed to the U.S. embassy in Saigon in Cable 243.

The Central Intelligence Agency (CIA) was in contact with generals planning to remove Diem. They were told that the United States would not oppose such a move nor punish the generals by cutting off aid. President Diem was overthrown and executed, along with his brother, on 2 November 1963. When he was informed, Maxwell Taylor remembered that Kennedy "rushed from the room with a look of shock and dismay on his face." He had not approved Diem's murder. The U.S. ambassador to South Vietnam, Henry Cabot Lodge, invited the coup leaders to the embassy and congratulated them. Ambassador Lodge informed Kennedy that "the prospects now are for a shorter war".

Following the coup, chaos ensued. Hanoi took advantage of the situation and increased its support for the guerrillas. South Vietnam entered a period of extreme political instability, as one military government toppled another in quick succession. Increasingly, each new regime was viewed as a puppet of the Americans; whatever the failings of Diem, his credentials as a nationalist (as Robert McNamara later reflected) had been impeccable.

U.S military advisers were embedded at every level of the South Vietnamese armed forces. They were, however, almost completely ignorant of the political nature of the insurgency. The insurgency was a political power struggle, in which military engagements were not the main goal. The Kennedy administration sought to refocus U.S. efforts on pacification and "winning over the hearts and minds" of the population. The military leadership in Washington, however, was hostile to any role for U.S. advisers other than conventional troop training. General Paul Harkins, the commander of U.S. forces in South Vietnam, confidently predicted victory by Christmas 1963. The CIA was less optimistic, however, warning that "the Viet Cong by and large retain de facto control of much of the countryside and have steadily increased the overall intensity of the effort".

Paramilitary officers from the CIA's Special Activities Division trained and led Hmong tribesmen in Laos and into Vietnam. The indigenous forces numbered in the tens of thousands and they conducted direct action missions, led by paramilitary officers, against the Communist Pathet Lao forces and their North Vietnamese supporters. The CIA also ran the Phoenix Program and participation Military Assistance Command, Vietnam – Studies and Observations Group (MAC-V SOG), which was originally named the Special Operations Group, but was changed for cover purposes.

Lyndon B. Johnson escalates the war, 1963–1969
Lyndon B. Johnson (LBJ), as he took over the presidency after the death of Kennedy, initially did not consider Vietnam a priority and was more concerned with his "Great Society" and progressive social programs. Presidential aide Jack Valenti recalls, "Vietnam at the time was no bigger than a man's fist on the horizon. We hardly discussed it because it was not worth discussing."

On 24 November 1963, Johnson said, "the battle against communism... must be joined... with strength and determination." The pledge came at a time when Vietnam was deteriorating, especially in places like the Mekong Delta, because of the recent coup against Diem. Johnson had reversed Kennedy's disengagement policy from Vietnam in withdrawing 1,000 troops by the end of 1963 (NSAM 263 on 11 October), with his own NSAM 273 (26 November) to expand the war.

The military revolutionary council, meeting in lieu of a strong South Vietnamese leader, was made up of 12 members headed by General Duong Van Minh—whom Stanley Karnow, a journalist on the ground, later recalled as "a model of lethargy." Lodge, frustrated by the end of the year, cabled home about Minh: "Will he be strong enough to get on top of things?" His regime was overthrown in January 1964 by General Nguyen Khanh. However, there was persistent instability in the military as several coups—not all successful—occurred in a short space of time. On 2 August 1964, the USS Maddox, on an intelligence mission along North Vietnam's coast, allegedly fired upon and damaged several torpedo boats that had been stalking it in the Gulf of Tonkin. A second attack was reported two days later on the USS Turner Joy and Maddox in the same area. The circumstances of the attack were murky. Lyndon Johnson commented to Undersecretary of State George Ball that "those sailors out there may have been shooting at flying fish."

The second attack led to retaliatory air strikes, prompted Congress to approve the Gulf of Tonkin Resolution on 5 August 1964, signed by Johnson, and gave the President power to conduct military operations in Southeast Asia without declaring war. Although Congressmen at the time denied that this was a full scale war declaration, the Tonkin Resolution allowed the President unilateral power to launch a full scale war if the President deemed necessary. In the same month, Johnson pledged that he was not "... committing American boys to fighting a war that I think ought to be fought by the boys of Asia to help protect their own land."

An undated NSA publication declassified in 2005, however, revealed that there was no attack on 4 August. It had already been called into question long before this. "Gulf of Tonkin incident", writes Louise Gerdes, "is an oft-cited example of the way in which Johnson misled the American people to gain support for his foreign policy in Vietnam." George C. Herring argues, however, that McNamara and the Pentagon "did not knowingly lie about the alleged attacks, but they were obviously in a mood to retaliate and they seem to have selected from the evidence available to them those parts that confirmed what they wanted to believe."

"From a strength of approximately 5,000 at the start of 1959 the Viet Cong's ranks grew to about 100,000 at the end of 1964...Between 1961 and 1964 the Army's strength rose from about 850,000 to nearly a million men." The numbers for U.S. troops deployed to Vietnam during the same period were quite different; 2,000 in 1961, rising rapidly to 16,500 in 1964. The National Security Council recommended a three-stage escalation of the bombing of North Vietnam. On 2 March 1965, following an attack on a U.S. Marine barracks at Pleiku, Operation Flaming Dart (initiated when Soviet Premier Alexei Kosygin was at a state visit to North Vietnam), Operation Rolling Thunder and Operation Arc Light commenced. The bombing campaign, which ultimately lasted three years, was intended to force North Vietnam to cease its support for the National Front for the Liberation of South Vietnam (NLF) by threatening to destroy North Vietnam's air defenses and industrial infrastructure. As well, it was aimed at bolstering the morale of the South Vietnamese. Between March 1965 and November 1968, "Rolling Thunder" deluged the north with a million tons of missiles, rockets and bombs.

Bombing was not restricted to North Vietnam. Other aerial campaigns, such as Operation Commando Hunt, targeted different parts of the NLF and VPA infrastructure. These included the Ho Chi Minh trail, which ran through Laos and Cambodia. The objective of forcing North Vietnam to stop its support for the NLF, however, was never reached. As one officer noted "this is a political war and it calls for discriminate killing. The best weapon... would be a knife... The worst is an airplane." The Chief of Staff of the United States Air Force Curtis LeMay, however, had long advocated saturation bombing in Vietnam and wrote of the Communists that "we're going to bomb them back into the Stone Age".

Escalation and ground war
After several attacks upon them, it was decided that U.S. Air Force bases needed more protection. The South Vietnamese military seemed incapable of providing security. On 8 March 1965, 3,500 U.S. Marines were dispatched to South Vietnam. This marked the beginning of the American ground war. U.S. public opinion overwhelmingly supported the deployment.

In a statement similar to that made to the French almost two decades earlier, Ho Chi Minh warned that if the Americans "want to make war for twenty years then we shall make war for twenty years. If they want to make peace, we shall make peace and invite them to afternoon tea." As former First Deputy Foreign Minister Tran Quang Co has noted, the primary goal of the war was to reunify Vietnam and secure its independence. The policy of the Democratic Republic of Vietnam (DRV) was not to topple other non-communist governments in South East Asia.

The Marines' assignment was defensive. The initial deployment of 3,500 in March was increased to nearly 200,000 by December. The U.S. military had long been schooled in offensive warfare. Regardless of political policies, U.S. commanders were institutionally and psychologically unsuited to a defensive mission. In December, ARVN forces suffered heavy losses at the Battle of Bình Giã, in a battle that both sides viewed as a watershed. Previously communist forces had utilized hit-and-run guerrilla tactics, however at Binh Gia they had defeated a strong ARVN force in conventional warfare. Tellingly, South Vietnamese forces were again defeated in June, at the Battle of Đồng Xoài. Desertion rates were increasing, and morale plummeted. General William Westmoreland informed Admiral U.S. Grant Sharp, Jr., commander of U.S. Pacific forces, that the situation was critical. He said, "I am convinced that U.S. troops with their energy, mobility, and firepower can successfully take the fight to the NLF [National Front for the Liberation of South Vietnam]." With this recommendation, Westmoreland was advocating an aggressive departure from America's defensive posture and the sidelining of the South Vietnamese. By ignoring ARVN units, the U.S. commitment became open-ended. Westmoreland outlined a three-point plan to win the war: The plan was approved by Johnson and marked a profound departure from the previous administration's insistence that the government of South Vietnam was responsible for defeating the guerrillas. Westmoreland predicted victory by the end of 1967. Johnson did not, however, communicate this change in strategy to the media. Instead he emphasized continuity. The change in U.S. policy depended on matching the North Vietnamese and the NLF in a contest of attrition and morale. The opponents were locked in a cycle of escalation. The idea that the government of South Vietnam could manage its own affairs was shelved. The one-year tour of duty deprived units of experienced leadership. As one observer noted "we were not in Vietnam for 10 years, but for one year 10 times." As a result, training programs were shortened.
 * Phase 1. Commitment of U.S. (and other free world) forces necessary to halt the losing trend by the end of 1965.
 * Phase 2. U.S. and allied forces mount major offensive actions to seize the initiative to destroy guerrilla and organized enemy forces. This phase would end when the enemy had been worn down, thrown on the defensive, and driven back from major populated areas.
 * Phase 3. If the enemy persisted, a period of twelve to eighteen months following Phase 2 would be required for the final destruction of enemy forces remaining in remote base areas.

South Vietnam was inundated with manufactured goods. As Stanley Karnow writes, "the main PX [Post Exchange], located in the Saigon suburb of Cholon, was only slightly smaller than the New York Bloomingdale's..." The American buildup transformed the economy and had a profound effect on South Vietnamese society. A huge surge in corruption was witnessed. Washington encouraged its SEATO allies to contribute troops. Australia, New Zealand, the Republic of Korea, Thailand, and the Philippines all agreed to send troops. Major allies, however, notably NATO nations Canada and the United Kingdom, declined Washington's troop requests. The U.S. and its allies mounted complex operations, such as operations Masher, Attleboro, Cedar Falls, and Junction City. However, the communist insurgents remained elusive and demonstrated great tactical flexibility.

Meanwhile, the political situation in South Vietnam began to stabilize with the coming to power of Prime Minister Air Marshal Nguyễn Cao Kỳand figurehead Chief of State, General Nguyễn Văn Thiệu, in mid 1965 at the head of a military junta. This ended a series of coups that had happened more than once a year. In 1967, Thieu became president with Ky as his deputy, after rigged elections. Although they were nominally a civilian government, Ky was supposed to maintain real power through a behind-the-scenes military body. However, Thieu outmanoevred and sidelined Ky by filling the ranks with generals from his faction. Thieu was also accused of murdering Ky loyalists through contrived military accidents. Thieu, mistrustful and indecisive, remained president until 1975, having won a one-man election in 1971.

The Johnson administration employed a "policy of minimum candor" in its dealings with the media. Military information officers sought to manage media coverage by emphasizing stories that portrayed progress in the war. Over time, this policy damaged the public trust in official pronouncements. As the media's coverage of the war and that of the Pentagon diverged, a so-called credibility gap developed.

Tet Offensive
Having lured General Westmoreland's forces into the hinterland at Khe Sanh in Quảng Trị Province, in January 1968, the NVA and NLF broke the truce that had traditionally accompanied the Tết (Lunar New Year) holiday. They launched the surprise Tet Offensive in the hope of sparking a national uprising. Over 100 cities were attacked, with assaults on General Westmoreland's headquarters and the U.S. Embassy, Saigon.

Although the U.S. and South Vietnamese forces were initially taken aback by the scale of the urban offensive, they responded quickly and effectively, decimating the ranks of the NLF. In the former capital city of Huế, the combined NLF and VPA troops captured the Imperial Citadel and much of the city, which led to the Battle of Huế. Throughout the offensive, the American forces employed massive firepower; in Huế where the battle was the fiercest, that firepower left 80% of the city in ruins. During the interim between the capture of the Citadel and end of the "Battle of Huế", the communist insurgent occupying forces massacred several thousand unarmed Huế civilians (estimates vary up to a high of 6,000). After the war, North Vietnamese officials acknowledged that the Tet Offensive had, indeed, caused grave damage to NLF forces. But the offensive had another, unintended consequence.

General Westmoreland had become the public face of the war. He was featured on the cover of Time magazine three times and was named 1965's Man of the Year. Time described him as "the sinewy personification of the American fighting man... (who) directed the historic buildup, drew up the battle plans, and infused the... men under him with his own idealistic view of U.S. aims and responsibilities." In November 1967 Westmoreland spearheaded a public relations drive for the Johnson administration to bolster flagging public support. In a speech before the National Press Club he said that a point in the war had been reached "where the end comes into view." Thus, the public was shocked and confused when Westmoreland's predictions were trumped by Tet. The American media, which had been largely supportive of U.S. efforts, rounded on the Johnson administration for what had become an increasing credibility gap. Despite its military failure, the Tet Offensive became a political victory and ended the career of President Lyndon B. Johnson, who declined to run for re-election. Johnson's approval rating slumped from 48 to 36 percent.

As James Witz noted, Tet "contradicted the claims of progress... made by the Johnson administration and the military." The Tet Offensive was the turning point in America's involvement in the Vietnam War. It had a profound impact on domestic support for the conflict. The offensive constituted an intelligence failure on the scale of Pearl Harbor. Journalist Peter Arnett quoted an unnamed officer, saying of Bến Tre (laid to rubble by U.S. firepower) that "it became necessary to destroy the village in order to save it" (though the authenticity of this quote is disputed). According to one source, this quote was attributed to Major Booris of 9th Infantry Division. Westmoreland became Chief of Staff of the Army in March, just as all resistance was finally subdued. The move was technically a promotion. However, his position had become untenable because of the offensive and because his request for 200,000 additional troops had been leaked to the media. Westmoreland was succeeded by his deputy Creighton Abrams, a commander less inclined to public media pronouncements.

On 10 May 1968, despite low expectations, peace talks began between the United States and the Democratic Republic of Vietnam. Negotiations stagnated for five months, until Johnson gave orders to halt the bombing of North Vietnam. The Democratic candidate, Vice President Hubert Humphrey, was running against Republican former vice president Richard Nixon.

As historian Robert Dallek writes, "Lyndon Johnson's escalation of the war in Vietnam divided Americans into warring camps... cost 30,000 American lives by the time he left office, (and) destroyed Johnson's presidency..." His refusal to send more U.S. troops to Vietnam was seen as Johnson's admission that the war was lost. It can be seen that the refusal was a tacit admission that the war could not be won by escalation, at least not at a cost acceptable to the American people. As Secretary of Defense Robert McNamara noted, "the dangerous illusion of victory by the United States was therefore dead."

Nixon Doctrine / Vietnamization
Severe communist losses during the Tet Offensive allowed U.S. President Richard Nixon to begin troop withdrawals. His plan, called the Nixon Doctrine, was to build up the ARVN, so that they could take over the defense of South Vietnam. The policy became known as "Vietnamization". Vietnamization had much in common with the policies of the Kennedy administration. One important difference, however, remained. While Kennedy insisted that the South Vietnamese fight the war themselves, he attempted to limit the scope of the conflict.

Nixon said in an announcement, "I am tonight announcing plans for the withdrawal of an additional 150,000 American troops to be completed during the spring of next year. This will bring a total reduction of 265,500 men in our armed forces in Vietnam below the level that existed when we took office 15 months ago."

On 10 October 1969, Nixon ordered a squadron of 18 B-52s loaded with nuclear weapons to race to the border of Soviet airspace to convince the Soviet Union that he was capable of anything to end the Vietnam War.

Nixon also pursued negotiations. Theater commander Creighton Abrams shifted to smaller operations, aimed at communist logistics, with better use of firepower and more cooperation with the ARVN. Nixon also began to pursue détente with the Soviet Union and rapprochement with the People's Republic of China. This policy helped to decrease global tensions. Détente led to nuclear arms reduction on the part of both superpowers. But Nixon was disappointed that the PRC and the Soviet Union continued to supply the North Vietnamese with aid. In September 1969, Ho Chi Minh died at age seventy-nine.

The anti-war movement was gaining strength in the United States. Nixon appealed to the "silent majority" of Americans to support the war. But revelations of the My Lai Massacre, in which a U.S. Army platoon raped and killed civilians, and the 1969 "Green Beret Affair" where eight Special Forces soldiers, including the 5th Special Forces Group Commander were arrested for the murder of a suspected double agent provoked national and international outrage.

Beginning in 1970, American troops were being taken away from border areas where much more killing took place, and instead put along the coast and interior, which is one reason why casualties in 1970 were less than half of 1969's totals.

The secret bombing of Cambodia and Laos
Prince Norodom Sihanouk had proclaimed Cambodia neutral since 1955, but the communists used Cambodian soil as a base and Sihanouk tolerated their presence, because he wished to avoid being drawn into a wider regional conflict. Under pressure from Washington, however, he changed this policy in 1969. The Vietnamese communists were no longer welcome. President Nixon took the opportunity to launch a massive secret bombing campaign, called Operation Menu, against their sanctuaries along the Cambodia/Vietnam border.

This violated a long succession of pronouncements from Washington supporting Cambodian neutrality. Richard Nixon wrote to Prince Sihanouk in April 1969 assuring him that the United States respected "the sovereignty, neutrality and territorial integrity of the Kingdom of Cambodia..." In 1970, Prince Sihanouk was deposed by his pro-American prime minister Lon Nol. The country's borders were closed, while U.S. forces and ARVN launched incursions into Cambodia to attack VPA/NLF bases and buy time for South Vietnam.

The invasion of Cambodia sparked nationwide U.S. protests. Four students were killed by National Guardsmen at Kent State University during a protest in Ohio, which provoked public outrage in the United States. The reaction to the incident by the Nixon administration was seen as callous and indifferent, providing additional impetus for the anti-war movement.

XXIn 1971 the Pentagon Papers were leaked to The New York Times. The top-secret history of U.S. involvement in Vietnam, commissioned by the Department of Defense, detailed a long series of public deceptions. The Supreme Court ruled that its publication was legal.XX

The ARVN launched Operation Lam Son 719 in February 1971, aimed at cutting the Ho Chi Minh trail in Laos. The ostensibly neutral Laos had long been the scene of a secret war. After meeting resistance, ARVN forces retreated in a confused rout. They fled along roads littered with their own dead. When they ran out of fuel, soldiers abandoned their vehicles and attempted to barge their way on to American helicopters sent to evacuate the wounded. Many ARVN soldiers clung to helicopter skids in a desperate attempt to save themselves. U.S. aircraft had to destroy abandoned equipment, including tanks, to prevent them from falling into enemy hands. Half of the invading ARVN troops were either captured or killed. The operation was a fiasco and represented a clear failure of Vietnamization. As Karnow noted "the blunders were monumental... The (South Vietnamese) government's top officers had been tutored by the Americans for ten or fifteen years, many at training schools in the United States, yet they had learned little."

In 1971 Australia and New Zealand withdrew their soldiers. The U.S. troop count was further reduced to 196,700, with a deadline to remove another 45,000 troops by February 1972. As peace protests spread across the United States, disillusionment and ill-discipline grew in the ranks.

Vietnamization was again tested by the Easter Offensive of 1972, a massive conventional invasion of South Vietnam. The VPA and NLF quickly overran the northern provinces and in coordination with other forces attacked from Cambodia, threatening to cut the country in half. U.S. troop withdrawals continued. But American airpower came to the rescue with Operation Linebacker, and the offensive was halted. However, it became clear that without American airpower South Vietnam could not survive. The last remaining American ground troops were withdrawn in August.

1972 election and Paris Peace Accords
The war was the central issue of the 1972 presidential election. Nixon's opponent, George McGovern, campaigned on a platform of withdrawal from Vietnam. Nixon's National Security Adviser, Henry Kissinger, continued secret negotiations with North Vietnam's Lê Ðức Thọ. In October 1972, they reached an agreement.

However, South Vietnamese President Thieu demanded massive changes to the peace accord. When North Vietnam went public with the agreement's details, the Nixon administration claimed that the North was attempting to embarrass the President. The negotiations became deadlocked. Hanoi demanded new changes. To show his support for South Vietnam and force Hanoi back to the negotiating table, Nixon ordered Operation Linebacker II, a massive bombing of Hanoi and Haiphong 18–29 December 1972. The offensive destroyed much of the remaining economic and industrial capacity of North Vietnam. Simultaneously Nixon pressured Thieu to accept the terms of the agreement, threatening to conclude a bilateral peace deal and cut off American aid.

On 15 January 1973, Nixon announced the suspension of offensive action against North Vietnam. The Paris Peace Accords on "Ending the War and Restoring Peace in Vietnam" were signed on 27 January 1973, officially ending direct U.S. involvement in the Vietnam War. A cease-fire was declared across North and South Vietnam. U.S. POWs were released. The agreement guaranteed the territorial integrity of Vietnam and, like the Geneva Conference of 1954, called for national elections in the North and South. The Paris Peace Accords stipulated a sixty-day period for the total withdrawal of U.S. forces. "This article", noted Peter Church, "proved... to be the only one of the Paris Agreements which was fully carried out."

Opposition to the Vietnam War: 1962–1975
Some advocates within the peace movement advocated a unilateral withdrawal of U.S. forces from Vietnam. One reason given for the withdrawal is that it would contribute to a lessening of tensions in the region and thus less human bloodshed. Early opposition to U.S. involvement in Vietnam was centered around the Geneva conference of 1954. American support of Diem in refusing elections was thought to be thwarting the very democracy that America claimed to be supporting. John Kennedy, while Senator, opposed involvement in Vietnam.

Opposition to the Vietnam War tended to unite groups opposed to U.S. anti-communism, imperialism and colonialism and, for those involved with the New Left such as the Catholic Worker Movement, capitalism itself. Others, such as Stephen Spiro opposed the war based on the theory of Just War. Some wanted to show solidarity with the people of Vietnam, such as Norman Morrison emulating the actions of Thích Quảng Đức. Some critics of U.S. withdrawal predicted that it would not contribute to peace but rather vastly increase bloodshed. These critics advocated U.S. forces remain until all threats from the Viet Cong and North Vietnamese Army had been eliminated. Advocates of U.S. withdrawal were generally known as "doves", and they called their opponents "hawks", following nomenclature dating back to the War of 1812.

High-profile opposition to the Vietnam War turned to street protests in an effort to turn U.S. political opinion. On 15 October 1969, the Vietnam Moratorium attracted millions of Americans. The fatal shooting of four students at Kent State University led to nation-wide university protests. Riots broke out at the 1968 Democratic National Convention. After explosive news reports of American military abuses, such as the 1968 My Lai Massacre, brought new attention and support to the anti-war movement, some veterans joined Vietnam Veterans Against the War. Anti-war protests ended with the final withdrawal of troops after the Paris Peace Accords were signed in 1973. South Vietnam was left to defend itself alone when the fighting resumed. Many South Vietnamese subsequently fled to the United States.

Exit of the Americans: 1973–1975
The United States began drastically reducing their troop support in South Vietnam during the final years of "Vietnamization". Many U.S. troops were removed from the region, and on 5 March 1971, the United States returned the 5th Special Forces Group, which was the first American unit deployed to South Vietnam, to its former base in Fort Bragg, North Carolina.

Under the Paris Peace Accords, between North Vietnamese Foreign Minister Lê Ðức Thọ and U.S. Secretary of State Henry Kissinger, and reluctantly signed by South Vietnamese President Thiệu, U.S. military forces withdrew from South Vietnam and prisoners were exchanged. North Vietnam was allowed to continue supplying communist troops in the South, but only to the extent of replacing materials that were consumed. Later that year the Nobel Peace Prize was awarded to Kissinger and Thọ, but the Vietnamese negotiator declined it saying that a true peace did not yet exist.

The communist leaders had expected that the ceasefire terms would favor their side. But Saigon, bolstered by a surge of U.S. aid received just before the ceasefire went into effect, began to roll back the Vietcong. The communists responded with a new strategy hammered out in a series of meetings in Hanoi in March 1973, according to the memoirs of Trần Văn Trà.

As the Vietcong's top commander, Trà participated in several of these meetings. With U.S. bombings suspended, work on the Ho Chi Minh Trail and other logistical structures could proceed unimpeded. Logistics would be upgraded until the North was in a position to launch a massive invasion of the South, projected for the 1975–76 dry season. Trà calculated that this date would be Hanoi's last opportunity to strike before Saigon's army could be fully trained. In the November 1972 Election, McGovern lost 49 of 50 states to Richard Nixon, who was re-elected U.S. president. Despite supporting Nixon over McGovern, many American voters split their tickets, returning a Democratic majority to both houses of Congress.

On 15 March 1973, U.S. President Richard Nixon implied that the United States would intervene militarily if the communist side violated the ceasefire. Public and congressional reaction to Nixon's trial balloon was unfavorable and in April Nixon appointed Graham Martin as U.S. ambassador to Vietnam. Martin was a second stringer compared to previous U.S. ambassadors and his appointment was an early signal that Washington had given up on Vietnam. During his confirmation hearings in June 1973,Secretary of Defense James R. Schlesinger stated that he would recommend resumption of U.S. bombing in North Vietnam if North Vietnam launched a major offensive against South Vietnam. On 4 June 1973, the U.S. Senate passed the Case-Church Amendment to prohibit such intervention.

The oil price shock of October 1973 caused significant damage to the South Vietnamese economy. The Vietcong resumed offensive operations when dry season began and by January 1974 it had recaptured the territory it lost during the previous dry season. After two clashes that left 55 South Vietnamese soldiers dead, President Thiệu announced on 4 January that the war had restarted and that the Paris Peace Accord was no longer in effect. There had been over 25,000 South Vietnamese casualties during the ceasefire period.

Gerald Ford took over as U.S. president on 9 August 1974 after President Nixon resigned due to the Watergate scandal. At this time, Congress cut financial aid to South Vietnam from $1 billion a year to $700 million. The U.S. midterm elections in 1974 brought in a new Congress dominated by Democrats who were even more determined to confront the president on the war. Congress immediately voted in restrictions on funding and military activities to be phased in through 1975 and to culminate in a total cutoff of funding in 1976.

The success of the 1973–74 dry season offensive inspired Trà to return to Hanoi in October 1974 and plead for a larger offensive in the next dry season. This time, Trà could travel on a drivable highway with regular fueling stops, a vast change from the days when the Ho Chi Minh Trail was a dangerous mountain trek. Giáp, the North Vietnamese defense minister, was reluctant to approve Trà's plan. A larger offensive might provoke a U.S. reaction and interfere with the big push planned for 1976. Trà appealed over Giáp's head to first secretary Lê Duẩn, who approved of the operation.

Trà's plan called for a limited offensive from Cambodia into Phuoc Long Province. The strike was designed to solve local logistical problems, gauge the reaction of South Vietnamese forces, and determine whether U.S. would return to the fray.

On 13 December 1974, North Vietnamese forces attacked Route 14 in Phuoc Long Province. Phuoc Binh, the provincial capital, fell on 6 January 1975. Ford desperately asked Congress for funds to assist and re-supply the South before it was overrun. Congress refused. The fall of Phuoc Binh and the lack of an American response left the South Vietnamese elite demoralized.

The speed of this success led the Politburo to reassess its strategy. It was decided that operations in the Central Highlands would be turned over to General Văn Tiến Dũng and that Pleiku should be seized, if possible. Before he left for the South, Dũng was addressed by Lê Duẩn: "Never have we had military and political conditions so perfect or a strategic advantage as great as we have now."

At the start of 1975, the South Vietnamese had three times as much artillery and twice the number of tanks and armoured cars as the opposition. They also had 1,400 aircraft and a two-to-one numerical superiority in combat troops over their Communist enemies. However, the rising oil prices meant that much of this could not be used. They faced a well-organized, highly determined and well-funded North Vietnam. Much of the North's material and financial support came from the communist bloc. Within South Vietnam, there was increasing chaos. Their abandonment by the American military had compromised an economy dependent on U.S. financial support and the presence of a large number of U.S. troops. South Vietnam suffered from the global recession that followed the Arab oil embargo.

Campaign 275
On 10 March 1975, General Dung launched Campaign 275, a limited offensive into the Central Highlands, supported by tanks and heavy artillery. The target was Buôn Ma Thuột, in Đắk Lắk Province. If the town could be taken, the provincial capital of Pleiku and the road to the coast would be exposed for a planned campaign in 1976. The ARVN proved incapable of resisting the onslaught, and its forces collapsed on 11 March. Once again, Hanoi was surprised by the speed of their success. Dung now urged the Politburo to allow him to seize Pleiku immediately and then turn his attention to Kon Tum. He argued that with two months of good weather remaining until the onset of the monsoon, it would be irresponsible to not take advantage of the situation.

President Nguyễn Văn Thiệu, a former general, was fearful that his forces would be cut off in the north by the attacking communists; Thieu ordered a retreat. The president declared this to be a "lighten the top and keep the bottom" strategy. But in what appeared to be a repeat of Operation Lam Son 719, the withdrawal soon turned into a bloody rout. While the bulk of ARVN forces attempted to flee, isolated units fought desperately. ARVN General Phu abandoned Pleiku and Kon Tum and retreated toward the coast, in what became known as the "column of tears".

As the ARVN tried to disengage from the enemy, refugees mixed in with the line of retreat. The poor condition of roads and bridges, damaged by years of conflict and neglect, slowed Phu's column. As the North Vietnamese forces approached, panic set in. Often abandoned by the officers, the soldiers and civilians were shelled incessantly. The retreat degenerated into a desperate scramble for the coast. By 1 April the "column of tears" was all but annihilated.

On 20 March, Thieu reversed himself and ordered Huế, Vietnam's third-largest city, be held at all costs, and then changed his policy several times. Thieu's contradictory orders confused and demoralized his officer corps. As the North Vietnamese launched their attack, panic set in, and ARVN resistance withered. On 22 March, the VPA opened the siege of Huế. Civilians flooded the airport and the docks hoping for any mode of escape. Some even swam out to sea to reach boats and barges anchored offshore. In the confusion, routed ARVN soldiers fired on civilians to make way for their retreat.

On 25 March, after a three-day battle, Huế fell. As resistance in Huế collapsed, North Vietnamese rockets rained down on Da Nang and its airport. By 28 March 35,000 VPA troops were poised to attack the suburbs. By 30 March 100,000 leaderless ARVN troops surrendered as the VPA marched victoriously through Da Nang. With the fall of the city, the defense of the Central Highlands and Northern provinces came to an end.

Final North Vietnamese offensive
With the northern half of the country under their control, the Politburo ordered General Dung to launch the final offensive against Saigon. The operational plan for the Ho Chi Minh Campaign called for the capture of Saigon before 1 May. Hanoi wished to avoid the coming monsoon and prevent any redeployment of ARVN forces defending the capital. Northern forces, their morale boosted by their recent victories, rolled on, taking Nha Trang, Cam Ranh, and Da Lat.

On 7 April, three North Vietnamese divisions attacked Xuan Loc, 40 miles (64 km) east of Saigon. The North Vietnamese met fierce resistance at Xuan Loc from the ARVN 18th Division, who were outnumbered six to one. For two bloody weeks, severe fighting raged as the ARVN defenders made a last stand to try to block the North Vietnamese advance. By 21 April, however, the exhausted garrison were ordered to withdraw towards Saigon.

An embittered and tearful President Thieu resigned on the same day, declaring that the United States had betrayed South Vietnam. In a scathing attack, he suggested U.S. Secretary of State Henry Kissinger had tricked him into signing the Paris peace agreement two years ago, promising military aid that failed to materialise. Having transferred power to Tran Van Huong, he left for Taiwan on 25 April. At the same time, North Vietnamese tanks had reached Bien Hoa and turned toward Saigon, brushing aside isolated ARVN units along the way.

By the end of April, the ARVN had collapsed on all fronts except in the Mekong Delta. Thousand of refugees streamed southward, ahead of the main communist onslaught. On 27 April 100,000 North Vietnamese troops encircled Saigon. The city was defended by about 30,000 ARVN troops. To hasten a collapse and foment panic, the VPA shelled the airport and forced its closure. With the air exit closed, large numbers of civilians found that they had no way out.

Fall of Saigon
Chaos, unrest, and panic broke out as hysterical South Vietnamese officials and civilians scrambled to leave Saigon. Martial law was declared. American helicopters began evacuating South Vietnamese, U.S., and foreign nationals from various parts of the city and from the U.S. embassy compound. Operation Frequent Wind had been delayed until the last possible moment, because of U.S. Ambassador Graham Martin's belief that Saigon could be held and that a political settlement could be reached.

Schlesinger announced early in the morning of 29 April 1975 the evacuation from Saigon by helicopter of the last U.S. diplomatic, military, and civilian personnel. Frequent Wind was arguably the largest helicopter evacuation in history. It began on 29 April, in an atmosphere of desperation, as hysterical crowds of Vietnamese vied for limited space. Martin pleaded with Washington to dispatch $700 million in emergency aid to bolster the regime and help it mobilize fresh military reserves. But American public opinion had soured on this conflict.

In the United States, South Vietnam was perceived as doomed. President Gerald Ford had given a televised speech on 23 April, declaring an end to the Vietnam War and all U.S. aid. Frequent Wind continued around the clock, as North Vietnamese tanks breached defenses on the outskirts of Saigon. In the early morning hours of 30 April, the last U.S. Marines evacuated the embassy by helicopter, as civilians swamped the perimeter and poured into the grounds. Many of them had been employed by the Americans and were left to their fate.

On 30 April 1975, VPA troops overcame all resistance, quickly capturing key buildings and installations. A tank crashed through the gates of the Independence Palace, and at 11:30 am local time the NLF flag was raised above it. President Duong Van Minh, who had succeeded Huong two days earlier, surrendered. His surrender marked the end of 116 years of Vietnamese involvement in conflict either alongside or against various countries, primarily France, China, Japan, Britain, and America.

People's Republic of China
In 1950, the People's Republic of China extended diplomatic recognition to the Viet Minh's Democratic Republic of Vietnam and sent weapons, as well as military advisors led by Luo Guibo to assist the Viet Minh in its war with the French. The first draft of the 1954 Geneva Accords was negotiated by French Prime Minister Pierre Mendès France and Chinese Premier Zhou Enlai who, fearing U.S. intervention, urged the Viet Minh to accept a partition at the 17th parallel.

China's ability to aid the Viet Minh declined when Soviet aid to China was reduced following the end of the Korean War in 1953. Moreover, a divided Vietnam posed less of a threat to China. China provided material and technical support to the Vietnamese communists worth hundreds of millions of dollars. Chinese-supplied rice allowed North Vietnam to pull military-age men from the paddies and to impose a universal draft beginning in 1960.

In the summer of 1962, Mao Zedong agreed to supply Hanoi with 90,000 rifles and guns free of charge. Starting in 1965, China sent anti-aircraft units and engineering battalions to North Vietnam to repair the damage caused by American bombing, rebuild roads and railroads, and to perform other engineering works. This freed North Vietnamese army units for combat in the South.

Sino-Soviet relations soured after the Soviets invaded Czechoslovakia in August 1968. In October, the Chinese demanded North Vietnam cut relations with Moscow, but Hanoi refused. The Chinese began to withdraw in November 1968 in preparation for a clash with the Soviets, which occurred at Zhenbao Island in March 1969. The Chinese also began financing the Khmer Rouge as a counterweight to the Vietnamese communists at this time. China's withdrawal from Vietnam was completed in July 1970.

The Khmer Rouge launched ferocious raids into Vietnam in 1975–1978. Vietnam responded with an invasion that toppled the Khmer Rouge. In response, China launched a brief, punitiveinvasion of Vietnam in 1979.

Soviet Union
Soviet ships in the South China Sea gave vital early warnings to NLF forces in South Vietnam. The Soviet intelligence ships would pick up American B-52 bombers flying from Okinawa and Guam. Their airspeed and direction would be noted and then relayed to COSVN headquarters. COSVN using airspeed and direction would calculate the bombing target and tell any assets to move "perpendicularly to the attack trajectory." These advance warning gave them time to move out of the way of the bombers and while the bombing runs caused extensive damage, because of the early warnings from 1968–1970 they did not kill a single military or civilian leader in the headquarter complexes.

The Soviet Union supplied North Vietnam with medical supplies, arms, tanks, planes, helicopters, artillery, anti-aircraft missiles and other military equipment. Soviet crews fired USSR-made surface-to-air missiles at the B-52 bombers, which were the first raiders shot down over Hanoi. Fewer than a dozen Soviet citizens lost their lives in this conflict. Following the collapse of the Soviet Union in 1991, Russian officials acknowledged that the Soviet Union had stationed up to 3,000 troops in Vietnam during the war.

Some Russian sources give more specific numbers: the hardware donated by the USSR included 2,000 tanks, 7,000 artillery guns, over 5,000 anti-aircraft guns, 158 surface-to-air rocket launchers. Over the course of the war the Soviet money donated to the Vietnamese cause was equal to 2 million dollars a day. From July 1965 to the end of 1974, fighting in Vietnam was attended by some 6,500 officers and generals, as well as more than 4,500 soldiers and sergeants of the Soviet Armed Forces. In addition, military schools and academies of the USSR began training Vietnamese soldiers – more than 10 thousand people.

North Korea
As a result of a decision of the Korean Workers' Party in October 1966, in early 1967 North Korea sent a fighter squadron to North Vietnam to back up the North Vietnamese 921st and 923rd fighter squadrons defending Hanoi. They stayed through 1968, and 200 pilots were reported to have served.

In addition, at least two anti-aircraft artillery regiments were sent as well. North Korea also sent weapons, ammunition and two million sets of uniforms to their comrades in North Vietnam. Kim Il-sung is reported to have told his pilots to "fight in the war as if the Vietnamese sky were their own".

Cuba
The extent of manpower contributions to North Vietnam by the communist Republic of Cuba, under Fidel Castro, is still a matter of debate. Then and since, the communist Vietnamese and Cuban governments have not divulged any information on this matter. There are numerous reports by former U.S. prisoners of war that Cuban military personnel were present at North Vietnamese prison facilities during the war, and that they participated in torture activities, in what is known as the "Cuba Program". Witnesses to this include Senator John McCain, 2008 U.S. Presidential candidate and former Vietnam prisoner of war, according to his 1999 book Faith of My Fathers. That there was at least a small contingent of Cuban military advisors present in North Vietnam during the war is without question. Some, notably Vietnam War POW/MIA issue advocates, claim evidence that Cuba's military and non-military involvement may have run into the "thousands" of personnel.

South Korea
On the anti-communist side, South Korea had the second-largest contingent of foreign troops in South Vietnam after the United States. In November 1961, Park Chung Hee proposed South Korean participation in the war to John F. Kennedy, but Kennedy disagreed. On 1 May 1964 Lyndon Johnson requested South Korean participation. The first South Korean troops began arriving in 1964 and large combat battalions began arriving a year later, with the South Koreans soon developing a reputation for effectiveness. Indeed arguably, they conducted counterinsurgency operations so well that American commanders felt that Korean area of responsibility was the safest.

Approximately 320,000 South Korean soldiers were sent to Vietnam, each serving a one year tour of duty. Maximum troop levels peaked at 50,000 in 1968, however all were withdrawn by 1973. About 5,000 South Koreans were killed and 11,000 were injured during the war. South Korea killed 41,000 Viet Congs. United States paid South Korean soldiers 235,560,000 dollars for their service in Vietnam, and South Korean GNP increased five times during the war.

Australia and New Zealand
Australia and New Zealand, close allies of the United States and members of the Southeast Asia Treaty Organization (SEATO) and the ANZUS military co-operation treaty, sent ground troops to Vietnam. Both nations had gained experience in counterinsurgency and jungle warfare during the Malayan Emergency and World War II. Their governments subscribed to the Domino theory. Australia began by sending advisors to Vietnam in 1962, and combat troops were committed in 1965. New Zealand began by sending a detachment of engineers and an artillery battery, and then started sending special forces and regular infantry which were attached to Australian formations. Australia's peak commitment was 7,672 combat troops and New Zealand's 552. More than 60,000 Australian personnel were involved during the course of the war, of which 521 were killed and more than 3,000 wounded. Approximately 3,000 New Zealanders served in Vietnam, losing 37 killed and 187 wounded. Most Australians and New Zealanders served in the 1st Australian Task Force in Phước Tuy province.

Philippines
Some 10,450 Filipino troops were dispatched to South Vietnam. They were primarily engaged in medical and other civilian pacification projects. These forces operated under the designation PHLCAG-V or Philippine Civic Action Group-Vietnam.

Thailand
Thai Army formations, including the "Queen's Cobra" battalion, saw action in South Vietnam between 1965 and 1971. Thai forces saw much more action in the covert war in Laos between 1964 and 1972, though Thai regular formations there were heavily outnumbered by the irregular "volunteers" of the CIA-sponsored Police Aerial Reconnaissance Units or PARU, who carried out reconnaissance activities on the western side of the Ho Chi Minh Trail.

Nationalist China
Since November 1967, the Chinese Nationalists on Taiwan secretly operated a cargo transport detachment to assist the United States and the ROV. Taiwan also provided military training units for the South Vietnamese diving units, later known as the Lien Doi Nguoi Nhai (LDMN) or Frogman unit in English. In addition to the diving trainers there were several hundred military personnel. Military commandos from Taiwan were captured by communist forces three times trying to infiltrate North Vietnam.

Canada and the ICC
Canada, India and Poland constituted the International Control Commission, which was supposed to monitor the 1954 ceasefire agreement. Officially, Canada did not have partisan involvement in the Vietnam War and diplomatically it was "non-belligerent". Victor Levant suggested otherwise in his book "Quiet Complicity: Canadian Involvement in the Vietnam War" (1986).'​

American nurses
During the Vietnam War, women served on active duty doing a variety of jobs. Early in 1963, the Army Nurse Corps (ANC) launched Operation Nightingale, an intensive effort to recruit nurses to serve in Vietnam. Most nurses who volunteered to serve in Vietnam came from predominantly working or middle class families with histories of military service. The majority of these women were white Catholics and Protestants. Because the need for medical aid was great, many nurses underwent a concentrated four-month training program before being deployed to Vietnam in the ANC Due to the shortage of staff, nurses usually worked twelve-hour shifts, six days per week and often suffered from exhaustion. First Lieutenant Sharon Lane was the only female military nurse to be killed by enemy gunfire during the war on 8 June 1969.

At the start of the Vietnam War, it was commonly thought that American women had no place in the military. Their traditional place had been in the domestic sphere, but with the war came opportunity for the expansion of gender roles. In Vietnam, women held a variety of jobs which included operating complex data processing equipment and serving as stenographers. Although a small number of women were assigned to combat zones, they were never allowed directly in the field of battle. The women who served in the military were solely volunteers. They faced a plethora of challenges, one of which was the relatively small number of female soldiers. Living in a male-dominated environment created tensions between the sexes. While this high male to female ratio was often uncomfortable for women, many men reported that having women in the field with them boosted their morale. Although this was not the women's purpose, it was one positive result of the their service. By 1973, approximately 7,500 women had served in Vietnam in the Southeast Asian theater. In that same year, the military lifted the prohibition on women entering the armed forces.

American women serving in Vietnam were subject to societal stereotypes. Many Americans either considered female in Vietnam mannish for living under the army discipline, or judged them to be women of questionable moral character who enlisted for the sole purpose of seducing men. To address this problem, the ANC released advertisements portraying women in the ANC as "proper, professional and well protected." (26) This effort to highlight the positive aspects of a nursing career reflected the ideas of second-wave feminism that occurred during the 1960s–1970s in the United States. Although female military nurses lived in a heavily male environment, very few cases of sexual harassment were ever reported. In 2008, by contrast, approximately one-third of women in the military felt that they had been sexually harassed compared with one-third of men.

Vietnamese women
Unlike the American women who went to Vietnam, Vietnamese women fought in the combat zone as well as provided manual labor to keep the Ho Chi Minh Trail open; they also worked in the rice fields to provide food for their families and the war effort. Women were enlisted in both the North Vietnamese Army (NVA) and the VietCong guerrilla force in South Vietnam.

Nguyen Thi Dinh was an example of a woman who had fought most of her adult life against foreign forces in her country. She was a member of the Vietminh fighting against the French and was imprisoned in the 1940s but on her release continued to fight and led a revolt in 1945 in Ben Tre and also in 1960 against Diems government. In the mid 1960s, she became a deputy commander of the Viet Cong, the highest ranking combat position held by a woman during the war.

Nguyen Thi Duc Hoan, who would later go on to be an actress-director, also joined the fight at a young age and would later become a guerrilla fighter against the Americans, at the time her own daughter was training in the militia.

Weapons
Communist forces were principally armed with Chinese and Soviet weaponry though some Viet Cong guerrilla units were equipped with Western infantry weapons either captured from French stocks during the first Indochina war or from ARVN units or requisitioned through illicit purchase. The ubiquitous Soviet AK-47 was widely regarded as the best assault rifle of the war and it was not uncommon to see U.S.special forces with captured AK-47s. The American M16, which replaced the M14, was considered more accurate and was lighter than the AK-47 but was prone to jamming. Oftentimes the gun suffered from a jamming flaw known as "failure to extract," which meant that a spent cartridge case remained lodged in the chamber after a bullet flew out the muzzle. According to a congressional report, the jamming was caused primarily by a change in gunpowder which was done without adequate testing and reflected a decision for which the safety of soldiers was a secondary consideration. The heavily armored, 90 mm M48A3 Patton tank saw extensive action during the Vietnam War and over 600 were deployed with US Forces. They played an important role in infantry support though there were few actual tank versus tank battles. The M67A1 flamethrower tank (nicknamed the Zippo) was an M48 variant used in Vietnam. Artillery was used extensively by both sides but the Americans were able to ferry the lightweight 105 mm M102 howitzer by helicopter to remote locations on quick notice. With its 17-mile (27 km) range, the Soviet 130 mm M-46 towed field gun was a highly regarded weapon and used to good effect by the NVA. It was countered by the long-range, American 175 mm M107 Self-Propelled Gun. The United States had air superiority though many aircraft were lost to surface-to-air missiles and anti-aircraft artillery. U.S. air power was credited with breaking the siege of Khe Sanh and blunting the 1972 Communist offensive against South Vietnam. At sea, the U.S. Navy had the run of the coastline, using aircraft carriers as platforms for offshore strikes and other naval vessels for offshore artillery support. Offshore naval fire played a pivotal role in the Battle for the city of Hue, providing accurate fire in support of the U.S. counter-offensive to retake the city. The Vietnam War was the first conflict that saw wide scale tactical deployment of helicopters. The Bell UH-1 Iroquois was used extensively in counter-guerilla operations both as a troop carrier and a gunship. In the latter role, the "Huey" as it became affectionately known, was outfitted with a variety of armaments including M60 machineguns, multi-barreled 7.62 mm Gatling guns and unguided air-to-surface rockets. The Hueys were also successfully used in MEDEVAC and search and rescue roles.

Events in Southeast Asia
Phnom Penh, the capital of Cambodia, fell to followers of the Communist Party of Kampuchea, commonly known as the Khmer Rouge, on 17 April 1975. Over the next four years, the Khmer Rouge enacted a genocidal policy that killed over one-fifth of all Cambodians, or more than a million people. After repeated border clashes in 1978, Vietnam invaded Democratic Kampuchea (Cambodia) and ousted the Khmer Rouge in the Cambodian–Vietnamese War.

In response, China invaded Vietnam in 1979. The two countries fought a brief border war, known as the Third Indochina War or the Sino-Vietnamese War. From 1978 to 1979, some 450,000 ethnic Chinese left Vietnam by boat as refugees or were expelled across the land border with China.

The Pathet Lao overthrew the royalist government of Laos in December 1975. They established the Lao People's Democratic Republic. From 1975 to 1996, the United States resettled some 250,000 Lao refugees from Thailand, including 130,000 Hmong.

More than 3 million people fled from Vietnam, Laos, and Cambodia, many as "boat people". Most Asian countries were unwilling to accept refugees. Since 1975, an estimated 1.4 million refugees from Vietnam and other Southeast Asian countries have been resettled to the United States, while Canada, Australia, and France resettled over 500,000.

Effect on the United States
In the post-war era, Americans struggled to absorb the lessons of the military intervention. As General Maxwell Taylor, one of the principal architects of the war, noted "first, we didn't know ourselves. We thought that we were going into another Korean War, but this was a different country. Secondly, we didn't know our South Vietnamese allies... And we knew less about North Vietnam. Who was Ho Chi Minh? Nobody really knew. So, until we know the enemy and know our allies and know ourselves, we'd better keep out of this kind of dirty business. It's very dangerous."

Some have suggested that "the responsibility for the ultimate failure of this policy [America's withdrawal from Vietnam] lies not with the men who fought, but with those in Congress..." Alternatively, the official history of the United States Army noted that "tactics have often seemed to exist apart from larger issues, strategies, and objectives. Yet in Vietnam the Army experienced tactical success and strategic failure... The...Vietnam War...legacy may be the lesson that unique historical, political, cultural, and social factors always impinge on the military...Success rests not only on military progress but on correctly analyzing the nature of the particular conflict, understanding the enemy's strategy, and assessing the strengths and weaknesses of allies. A new humility and a new sophistication may form the best parts of a complex heritage left to the Army by the long, bitter war in Vietnam." U.S. Secretary of State Henry Kissinger wrote in a secret memo to President Gerald Ford that "in terms of military tactics, we cannot help draw the conclusion that our armed forces are not suited to this kind of war. Even the Special Forces who had been designed for it could not prevail." Even Secretary of Defense Robert McNamara concluded that "the achievement of a military victory by U.S. forces in Vietnam was indeed a dangerous illusion."

Doubts surfaced as to the effectiveness of large-scale, sustained bombing. As Army Chief of Staff Harold Keith Johnson noted, "if anything came out of Vietnam, it was that air power couldn't do the job." Even General William Westmoreland admitted that the bombing had been ineffective. As he remarked, "I still doubt that the North Vietnamese would have relented."

The inability to bomb Hanoi to the bargaining table also illustrated another U.S. miscalculation. The North's leadership was composed of hardened communists who had been fighting for independence for thirty years. They had defeated the French, and their tenacity as both nationalists and communists was formidable. Ho Chi Minh is quoted as saying, "You can kill ten of my men for every one I kill of yours...But even at these odds you will lose and I will win."

The Vietnam War called into question the U.S. Army doctrine. Marine Corps General Victor H. Krulak heavily criticised Westmoreland's attrition strategy, calling it "wasteful of American lives... with small likelihood of a successful outcome." As well, doubts surfaced about the ability of the military to train foreign forces.

Between 1965 and 1975, the United States spent $111 billion on the war ($686 billion in FY2008 dollars). This resulted in a large federal budget deficit.

More than 3 million Americans served in the Vietnam War, some 1.5 million of whom actually saw combat in Vietnam. James E. Westheider wrote that "At the height of American involvement in 1968, for example, there were 543,000 American military personnel in Vietnam, but only 80,000 were considered combat troops." Conscription in the United States had been controlled by the President since World War II, but ended in 1973."

By war's end, 58,220 soldiers were killed, more than 150,000 were wounded, and at least 21,000 were permanently disabled. According to Dale Kueter, "Sixty-one percent of those killed were age 21 or younger. Of those killed in combat, 86.3 percent were white, 12.5 percent were black and the remainder from other races." The youngest American KIA in the war was PFC Dan Bullock, who had falsified his birth certificate and enlisted in the US Marines at age 14 and who was killed in combat at age 15. Approximately 830,000 Vietnam veterans suffered symptoms of posttraumatic stress disorder. An estimated 125,000 Americans fled to Canada to avoid the Vietnam draft, and approximately 50,000 American servicemen deserted. In 1977, United States President Jimmy Carter granted a full, complete and unconditional pardon to all Vietnam-era Draft dodgers. The Vietnam War POW/MIA issue, concerning the fate of U.S. service personnel listed as missing in action, persisted for many years after the war's conclusion.

Chemical defoliation
One of the most controversial aspects of the U.S. military effort in Southeast Asia was the widespread use of chemical defoliants between 1961 and 1971. They were used to defoliate large parts of the countryside. These chemicals continue to change the landscape, cause diseases and birth defects, and poison the food chain.

Early in the American military effort it was decided that since the enemy were hiding their activities under triple-canopy jungle, a useful first step might be to defoliate certain areas. This was especially true of growth surrounding bases (both large and small) in what became known as Operation Ranch Hand. Corporations like Dow Chemical Company and Monsanto were given the task of developing herbicides for this purpose.

The defoliants, which were distributed in drums marked with color-coded bands, included the "Rainbow Herbicides"—Agent Pink, Agent Green, Agent Purple, Agent Blue, Agent White, and, most famously, Agent Orange, which included dioxin as a by-product of its manufacture. About 12 million gallons (45,000,000 L) of Agent Orange were sprayed over Southeast Asia during the American involvement. A prime area of Ranch Hand operations was in the Mekong Delta, where the U.S. Navy patrol boats were vulnerable to attack from the undergrowth at the water's edge.

In 1961 and 1962, the Kennedy administration authorized the use of chemicals to destroy rice crops. Between 1961 and 1967, the U.S. Air Force sprayed 20 million U.S. gallons (75,700,000 L) of concentrated herbicides over 6 million acres (24,000 km2) of crops and trees, affecting an estimated 13% of South Vietnam's land. In 1965, 42% of all herbicide was sprayed over food crops. Another purpose of herbicide use was to drive civilian populations into RVN-controlled areas.

As of 2006, the Vietnamese government estimates that there are over 4,000,000 victims of dioxin poisoning in Vietnam, although the United States government denies any conclusive scientific links between Agent Orange and the Vietnamese victims of dioxin poisoning. In some areas of southern Vietnam dioxin levels remain at over 100 times the accepted international standard.

The U.S. Veterans Administration has listed prostate cancer, respiratory cancers, multiple myeloma, Diabetes mellitus type 2, B-cell lymphomas, soft-tissue sarcoma, chloracne, porphyria cutanea tarda, peripheral neuropathy, and spina bifida in children of veterans exposed to Agent Orange. Although there has been much discussion over whether the use of these defoliants constituted a violation of the laws of war, the defoliants were not considered weapons, since exposure to them did not lead to immediate death or incapacitation.

Casualties
The number of military and civilian deaths from 1955 to 1975 is debated. Some reports fail to include the members of South Vietnamese forces killed in the final campaign, or the Royal Lao Armed Forces, thousands of Laotian and Thai irregulars, or Laotian civilians who all perished in the conflict. They do not include the tens of thousands of Cambodians killed during the civil war or the estimated one and one-half to two million that perished in the genocide that followed Khmer Rouge victory, or the fate of Laotian Royals and civilians after the Pathet Lao assumed complete power in Laos.

In 1995, the Vietnamese government reported that its military forces, including the NLF, suffered 1.1 million dead and 600,000 wounded during Hanoi's conflict with the United States. Civilian deaths were put at two million in the North and South, and economic reparations were demanded. Hanoi concealed the figures during the war to avoid demoralizing the population. Estimates of civilian deaths caused by American bombing in Operation Rolling Thunder range from 52,000 to 182,000. The U.S. military has estimated that between 200,000 and 250,000 South Vietnamese soldiers died in the war.

Popular culture
The Vietnam War has been featured heavily in television, film, video games, and literature in the participant countries. The war also influenced a generation of musicians and songwriters in Vietnam and the United States, both anti-war and pro/anti-communist. The band Country Joe and the Fish recorded "I-Feel-Like-I'm-Fixin'-To-Die Rag" / The "Fish" Cheer in 1965, and it became one of the most influential anti-Vietnam protest anthems.