1954–1975, War between communist North Vietnam and US-backed South Vietnam. Following the division of French Indochina into North and South Vietnam and the Vietnamese defeat of the French 1954, US involvement in Southeast Asia grew through the SEATO pact. Noncommunist South Vietnam was viewed, in the context of the 1950s and the cold war, as a bulwark against the spread of communism throughout SE Asia. Advisers and military aid were dispatched to the region at increasing levels because of the so-called domino theory, which contended that the fall of South Vietnam would precipitate the collapse of neighboring states. The US spent $141 bn in aid to the South Vietnamese government. Corruption and inefficiency within the South Vietnamese government led the US to assume ever greater responsibility for the war effort, until 1 million US combat troops were engaged.
In the US, the draft, the high war casualties, and the undeclared nature of the war resulted in growing domestic resistance, which caused social unrest and forced President Johnson to abandon reelection plans. President Nixon first expanded the war to Laos and Cambodia but finally phased out US involvement; his national security adviser Henry Kissinger negotiated a peace treaty 1973 with North Vietnam, which soon conquered the South and united the nation. Between 1961 and 1975, 56,555 US soldiers were killed; also some 200,000 South Vietnamese soldiers, plus 1 million North Vietnamese soldiers, and 500,000 civilians died.
Although US forces were never militarily defeated, Vietnam was considered a most humiliating political defeat for the US.
1954 Under the Geneva Convention the former French colony of Indochina was divided into the separate states of North and South Vietnam. Within South Vietnam the communist Viet Cong, supported by North Vietnam and China, attempted to seize power. The US began to provide military advisers to support the South Vietnamese.
1964 The Tonkin Gulf Incident, when North Vietnamese torpedo boats allegedly attacked two US destroyers, prompted the US to send troops.
1965The US declared combatant status 2 March and admitted using chemical weapons against Viet Cong forces 22 March.
1967 Several large-scale invasion attempts by North Vietnam were defeated by indigenous and US forces.
1968 Tet Offensive in South Vietnam; My Lai massacre by US troops.
1973 In the US, the unpopularity of sending troops to an undeclared war led to the start of US withdrawal. A peace treaty was signed between North and South Vietnam.
1975 South Vietnam was invaded by North Vietnam in March.
1976 South Vietnam was annexed by North Vietnam, and the two countries were renamed the Socialist Republic of Vietnam.
Following the Geneva agreement of 1954, there were five years of relative calm until 1959 relations between North and South Vietnam again became critical. The Ngo Dinh Diem regime in Saigon tried to eliminate the remaining Communists in the south, and the Communist government of Ho Chi Minh in Hanoi decided to assist a new rebellion south of the 17th parallel. By the end of 1960, the anti-Diem forces in the south had formed a national liberation front under the leadership of southern Communists and during 1961 Diem, who had depended on US aid since 1954, sought additional protection. General Maxwell Taylor went to Saigon Oct 1961 and President Kennedy decided against sending regular combat units to Vietnam but agreed to send “advisers”, many of whom were units of special forces expert in covert warfare. During 1961–62, a “strategic hamlet program” was initiated to improve security in the countryside, based on ideas borrowed from the British campaign against insurgents in Malaya. By the time of Kennedy’s death
Nov 1963 there were about 16,700 US troops in South Vietnam, and the situation was still far from under control. The main consequence of greater US involvement was that the North gave even more help to the communist national liberation front in the south.
During 1963, growing unrest against Ngo Dinh Diem led to more stringent repression culminating in a Buddhist rebellion May–Aug which caused the US government serious political embarrassment. Fearing that they would be accused of backing a dictatorship, they eventually decided to remove Ngo Dinh Diem. He was deposed by a military coup Nov 1963 and a committee of generals took over South Vietnam. Their regime proved even less satisfactory to the US however, and 1964 saw a mounting political crisis in Saigon.
During 1963 President Kennedy had planned to start reducing the American commitment, on the basis of optimistic reports that communist “insurgency” would be defeated by the end of 1965. After Kennedy’s death, President Johnson adopted a less cautious approach and during the course of 1964 allowed the preparation of plans for both covert operations and open air warfare against North Vietnam on the grounds that the latter was the real instigator of the war in the south. Despite his emphasis on peace during an election campaign against the more warlike Senator Goldwater, by the end of the year Johnson was virtually committed to escalation of the Vietnam conflict. After the Tonkin Gulf Incident Aug 1964, in which the US navy claimed that two of its ships were attacked by North Vietnamese patrol boats, Johnson secured from Congress a resolution which he later interpreted as allowing him to take unlimited action to resolve the crisis in Southeast Asia.
By early 1965 the communist guerrilla operations in the south were being dramatically stepped up. An attack on a US base at Pleiku Feb 1965 was used as the justification for starting air attacks on the north, which were to be a daily feature of the war until 1968. The US began sending in combat troops to Vietnam April 1965, and their numbers increased steadily until March 1968. The political crisis in Saigon was eased with the emergence of Nguyen Cao Ky as prime minister (1965–67), and the establishment of a new constitution 1966 and the election of Nguyen Van Thieu as president 1967. But the war situation became even more serious as US and South Vietnamese forces failed either to suppress the national liberation front in the south, or to destroy the determination of the leaders in Hanoi to drive the Americans out.
US resolve was seriously shaken Feb 1968 by the Tet Offensive, in which the communist Viet Cong guerrillas initiated major battles in Saigon, Hue, and a number of other towns. A crisis was reached in March 1968 when the US commander General Westmoreland asked for another 200,000 troops to go to Vietnam, on top of the 550,000 US personnel already there. By this time there were also Korean and Australian contingents deployed in Vietnam on top of the 400,000 South Vietnamese under arms. Faced with a serious monetary crisis at precisely the same moment, President Johnson decided against sending any more troops to Vietnam, and announced a limitation of bombing raids on the north. Before the end of 1968 the bombing had been halted completely and peace talks had opened in Paris; the US then began to reduce its ground forces in Vietnam. But the war dragged on throughout 1969–71 and spread throughout the region. In order to protect the still fragile situation in South Vietnam, US President Nixon spread the war to Camb
odia: he secured the removal of Prince Norodom Sihanouk's neutral regime of in Phnom Penh and began the heavy bombing of Cambodia which drew that country into the conflict. Heavy fighting also erupted in Laos at the same time, so that the war once again engulfed the whole of Indochina.
Anxious to break the stalemate, North Vietnam launched a new and much heavier offensive against the South Vietnamese army in Quang Tri province and in the region of An Loc (north of Saigon) spring 1972. There were now fewer than 100,000 US troops in Vietnam and so the Americans responded with intense bombing of the north, the mining of Haiphong harbor, and unlimited air support for South Vietnamese ground troops. This held the situation, but it became clear that it was only temporary. More serious contacts between Hanoi and Washington during 1972 led eventually to the signing of the Paris Treaty Jan 1973, a peace agreement between the two sides in South Vietnam and the US and North Vietnam, but not before a last bout of aerial bombardment against Hanoi Dec 1972 effectively destroyed the North's capacity for a further offensive for the next two years.
US forces finally left South Vietnam March 1973, and for two years the South Vietnamese government of Nguyen Van Thieu sought to continue the US policy of pacification. But the Viet Cong provisional revolutionary government of South Vietnam was making substantial political gains in the countryside and late 1974 North Vietnam breached the cease-fire with a final offensive against the South. By March 1975 South Vietnamese morale had collapsed, and in April the communist forces took Saigon with only a limited amount of fighting. The last Americans hastily evacuated Saigon by helicopter and several thousand Vietnamese refugees also fled the country. The war was over and Vietnam was reunited as the Socialist Republic of Vietnam July 1976.
A prolonged war (1954-1975) between the communist armies of North Vietnam who were supported by the Chinese and the non-communist armies of South Vietnam supported by the US.