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 Le Duc Tho. 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 January 15, 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 January 27, 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."

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.

In 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.

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.

Severe communist losses during the Tet Offensive allowed U.S. President Richard M. 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 October 10, 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.

The civilian cost of the war was again questioned when U.S. forces concluded operation Speedy Express with a claimed bodycount of 10,889 Communist guerillas with only 40 U.S. losses; Kevin Buckley writing in Newsweek estimated that perhaps 5,000 of the Vietnamese dead were civilians.

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.

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 NVA 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).^[160] 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 May 10, 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."

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 March 8, 1965, 3,500 United States 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, Army of the Republic of Vietnam (ARVN) forces suffered heavy losses at the Battle of Binh Gia,^[139] 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 successfully defeated a strong ARVN force in conventional warfare. Tellingly, South Vietnamese forces were again defeated in June, at the Battle of Dong Xoai.

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:

• 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.

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.

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 impact 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^[149] 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 Nguyen Cao Ky and 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.

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 November 24, 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 Oct. 11),^[118] with his own NSAM 273 (Nov. 26) 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 August 2, 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, and gave the president power to conduct military operations in Southeast Asia without declaring war. 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 August 4. It had already been called into question long before this. "The 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."^[108] 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 March 2, 1965, following an attack on a U.S. Marine barracks at Pleiku, Operation Flaming Dart, 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 Vietnam People's Army (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."^[133] 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".

When John F. Kennedy won the 1960 U.S. presidential election, one major issue Kennedy raised was whether the Soviet space and missile programs had surpassed those of the United States. As Kennedy took over, despite warnings from Eisenhower 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, John F. Kennedy bitterly disagreed with Soviet premier Nikita Khrushchev when they met in Vienna over key U.S.-Soviet issues. The legacy of the Korean War created the idea of a limited war.

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.

The Kennedy administration remained essentially committed to the Cold War foreign policy inherited from the Truman and Eisenhower administrations. In 1961, the USA 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 determined to "draw a line in the sand" and prevent a communist victory in Vietnam, saying, "Now we have a problem making our power credible and Vietnam looks like the place", to James Reston of The New York Times immediately after meeting Khrushchev in Vienna.

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 Army of the Republic of Vietnam (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.

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 July 23, 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 January 2, 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, and a Catholic who had been promoted due to religion and fidelity rather than skill, and whose main job was to preserve his forces to stave off coups; Cao 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, 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 Vesak 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 August 21, 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 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 November 2, 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 MAC-V SOG (Studies and Observations Group), which was originally named the Special Operations Group, but was changed for cover purposes.

The Domino Theory, which argued that if one country fell to communist forces, 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."

Rule

A devout Roman Catholic, Diem was fervently anti-communist, nationalist and socially conservative. Historian Luu Doan Huynh notes, however, that "Diem represented narrow and extremist nationalism coupled with autocracy and nepotism." As a wealthy Catholic, Diem was viewed by many ordinary Vietnamese 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 his dedication of the country to the Virgin Mary.

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

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

Robert McNamara wrote that the new American patrons 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, 1956–1960

The Sino-Soviet split led to a reduction in the influence of the PRC, which had insisted in 1954 that the Viet Minh accept a division of the country. Trường Chinh, North Vietnam's pro-PRC party first secretary, was demoted and Hanoi authorized communists in South Vietnam to begin a low level insurgency in December 1956. This insurgency in the south had begun in response to Diem's Denunciation of Communists campaign, in which thousands of local Viet Minh cadres and supporters had been executed or sent to concentration camps, and was in violation of the Northern Communist party line, which had enjoined them not to start an insurrection, but rather engage in a political campaign, agitating for a free all-Vietnam election in accordance with the Geneva accords.

Ho Chi Minh stated, "Do not engage in military operations; that will lead to defeat. Do not take land from a peasant. Emphasize nationalism rather than communism. Do not antagonize anyone if you can avoid it. Be selective in your violence. If an assassination is necessary, use a knife, not a rifle or grenade. It is too easy to kill innocent bystanders with guns and bombs, and accidental killing of the innocent bystanders will alienate peasants from the revolution. Once an assassination has taken place, make sure peasants know why the killing occurred." This strategy was referred to as "armed propaganda."

Soon afterward, Lê Duẩn, a communist leader who had been working in the South, returned to Hanoi to accept the position of acting first secretary, effectively replacing Trường. Duẩn urged a military line and advocated increased assistance to the insurgency. Four hundred government officials were assassinated in 1957 alone, and the violence gradually increased. While the terror was originally aimed at local government officials, it soon broadened to include other symbols of the status quo, such as schoolteachers, health workers, and agricultural officials. Village chiefs were Diem appointees from outside the villages and were hated by the peasantry for their corruption and abuse.) According to one estimate, 20 percent of South Vietnam's village chiefs had been assassinated by the insurgents by 1958. (The insurgency sought to completely destroy government control in South Vietnam's rural villages and replace it with a shadow government.

In January 1959, the North's Central Committee issued a secret resolution authorizing an "armed struggle". This authorized the southern communists to begin large-scale operations against the South Vietnamese military. North Vietnam supplied troops and supplies in earnest, and the infiltration of men and weapons from the north began along the Ho Chi Minh Trail. In May, South Vietnam enacted Law 10/59, which made political violence punishable by death and property confiscation.

Observing the increasing unpopularity of the Diem regime, on December 12, 1960, Hanoi authorized the creation of the National Liberation Front as a common front controlled by the communist party in the South.

Successive American administrations, as Robert McNamara and others have noted, overestimated the control that Hanoi had over the NLF.^[45] Diem's paranoia, repression, and incompetence progressively angered large segments of the population of South Vietnam. According to a November 1960 report by the head of the U.S. military advisory team, Lieutenant General Lionel C. McGarr, a "significant part" of the population in the south supported the communists. The communists thus had a degree of popular support for their campaign to bring down Diem and reunify the country.

Vietnam was temporarily partitioned at the 17th parallel, and under the terms of the Geneva Convention, civilians were to be given the opportunity to freely move 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 Diem 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 north for "regroupment" expecting to return to the South within 2 years. The Viet Minh left roughly 5,000 to 10,000 cadres in South Vietnam 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 their 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 DRV and engaged in a drastic land reform program in which an estimated eight thousand perceived "class enemies" were executed. In 1956 the Communist Party leaders of Hanoi admitted to "excesses" in implementing this program and restored a large amount of the land to the original owners.

In the south, former Emperor Bảo Đại's State of Vietnam operated, with Ngô Đình Diệm (appointed in July 1954) as his prime minister. In June 1955, Diem announced that elections would not be held. South Vietnam had rejected the agreement from the beginning and was therefore not bound by it, he said. "How can we expect 'free elections' to be held in the Communist North?" Diem asked. President Dwight D. 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.

In April–June 1955, Diem (against U.S. advice) cleared the decks of 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 October 23, 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. On October 26, 1955, Diem declared the new 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.

In January 1950, the communist nations, led by the People's Republic of China (PRC), recognized the Viet Minh's Democratic Republic of Vietnam as the government of Vietnam. Non-Communist nations recognized the French-backed State of Vietnam in Saigon led by former Emperor Bảo Đại 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.^[49] By 1954, the United States had supplied 300,000 small arms and spent US$1 billion in support of the French military effort and was 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 how seriously this was considered and by whom are even now vague and contradictory. One version of 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 Richard Nixon the plan involved the Joint Chiefs of Staff drawing up plans to use 3 small tactical nuclear weapons in support of the French. Vice president Richard Nixon, a so-called "hawk" on Vietnam, suggested that the United States might have to "put American boys in".^[54] President Eisenhower made American participation contingent on British support, but London was opposed. In the end, convinced that the political risks outweighed the possible benefits, Eisenhower decided against the intervention.

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 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. The Viet Minh and their mercurial commander Vo Nguyen Giap handed the French a stunning military defeat, and on May 7, 1954, the French Union garrison surrendered. At the Geneva Conference the French negotiated a ceasefire agreement with the Viet Minh. Independence was granted to Cambodia, Laos, and Vietnam.

France began its conquest of Indochina in the late 1850s, and completed the 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 the 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, controlled by the Communist Party of Vietnam, founded in 1941 and funded by United States and 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.

On May 1941, the Việt Minh was founded as a league for the independence from France. The Việt Minh also opposed Japanese occupation in 1945 for the same reason. The United States and Chinese national party supported them to weaken Japanese influence over Vietnam. However, they did not have enough power to fight actual battles at first. Ho Chi Minh was suspected of being a communist and jailed for a year by the Chinese national 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 March 9, 1945 and assumed direct control themselves^[33] through their puppet state of the Empire of Vietnam under Bảo Đại.

During 1944–1945, a deep famine struck northern Vietnam due to a combination of poor weather and French/Japanese exploitation. According to Ho chi Minh's speech in August, 1 million people died of starvation (out of a population of 10 million in the affected area). Exploiting the administrative gap^[35] 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. Into this vacuum, the Viet Minh entered and grasped power across Vietnam in the "August Revolution" (in large part supported by the Vietnamese population). After their defeat in the war, the Japanese Army gave weapons to the Vietnamese. To further help the nationalists, the Japanese 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.

On September 2, 1945, Ho Chi Minh, the leader of the Viet Minh, declared the independent Democratic Republic of Vietnam before a crowd of 500,000 in Hanoi. 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 that 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. When the British landed 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 and began killing off opposition politicians. The French landed in Hanoi by March 1946 and in November of that year they ousted the Viet Minh from the city. 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 Serai after the model of 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.

Vietnam War Statistic

Vietnam War
Part of the Cold War
Clockwise, from top left: U.S. Marines battle in Hamo village during the Tet Offensive, extraction of troops after an airmobile assault, a burning Viet Cong base camp in Mỹ Tho, Vietnamese civilians killed during the My Lai Massacre
Date November 1, 1955 (1955-11-01)[A 1] – April 30, 1975 (1975-04-30) Location South Vietnam, North Vietnam, Cambodia, Laos Result North Vietnamese victory Withdrawal of American forces from Indochina Dissolution of South Vietnam Communist takeover of Cambodia and Laos Territorial changes Unification of North and South Vietnam under North Vietnamese rule.
Belligerents
Anti-Communist forces: South Vietnam United States South Korea Australia Philippines New Zealand Thailand Khmer Republic Kingdom of Laos Republic of China	Communist forces: North Vietnam Viet Cong Khmer Rouge Pathet Lao People's Republic of China Soviet Union North Korea
Commanders and leaders
Ngô Đình Diệm Nguyễn Văn Thiệu Nguyễn Cao Kỳ Cao Van Vien Lyndon B. Johnson Richard Nixon William Westmoreland Creighton Abrams ...and others	Hồ Chí Minh Lê Duẩn Võ Nguyên Giáp Văn Tiến Dũng Trần Văn Trà Nguyen Van Linh ...and others
Strength
~1,830,000 (1968) South Vietnam: 850,000 United States: 536,100 Free World Forces: 65,000 South Korea: 312,853, Australia: 49,968 (1962–1973) Thailand, Philippines: 10,450 New Zealand: 3,890 (1964–1973)	~520,000 (1968) North Vietnam: ~340,000 PRC: 170,000 (1969) Soviet Union: 3,000 North Korea: 300
Casualties and losses
South Vietnam 220,357 dead;1,170,000 wounded United States 58,159 dead; 1,719 missing; 303,635 wounded South Korea 5,099 dead; 10,962 wounded; 4 missing Australia 520 dead;2,400*wounded New Zealand 37 dead; 187 wounded Thailand 1,351 dead Kingdom of Laos 30,000 killed, wounded unknown Total dead: 315,384 Total wounded: ~1,490,000+	North Vietnam & NLF 1,176,000 dead/missing; 600,000+ wounded P.R. China 1,446 dead; 4,200 wounded Soviet Union 16 dead Total dead: ~1,177,462 Total wounded: ~604,200+
South Vietnamese civilian dead: 1,581,000* Cambodian civilian dead: 700,000–1,000,000* North Vietnamese civilian dead: ~2,000,000 Laotian civilian dead: ~50,000* Total civilian dead: ~4,331,000