The Vietnam War (1959-1975) was a Cold War proxy war fought between the United States-backed South Vietnam and other Southeast Asian nationalist countries and the Soviet Union-backed North Vietnam and the Viet Cong, who were assisted by communist revolutionaries in Laos and Cambodia as well. The war was a defeat for the United States, who lost the war not because of military failure, but due to the negative public opinion of the war.
The division of Vietnam in 1954 led to open conflict by the end of the decade as the northern Communists sought to reunify the country under their leadership.
The Geneva Agreements of 1954 ended French rule over Vietnam and divided the country. Ho Chi Minh led the Communist-controlled Democratic Republic of Vietnam in the north; Ngo Dinh Diem led South Vietnam.
Diem's government was repressive and corrupt. In 1956 North Vietnam authorized southern Communists to begin an insurgency, sending cadres to the south to organize guerrilla war in 1959. These guerrillas were named the Viet Cong.
In November 1955, US President Dwight D. Eisenhower sent 740 men of the Military Assistance Advisory Group to train the South Vietnamese Army. Their arrival marked the official start of US military involvement in Vietnam.
In May 1961, President John F. Kennedy sent the first American troops - 400 US Army special forces (the Green Berets) - to South Vietnam to train its army in guerrilla tactics. Kennedy was concerned about rising communist strength across southeast Asia and saw South Vietnam as an important bulwark against this. By the time of his death in November 1963, Kennedy had increased troop numbers to 16,300.
By mid-1964 the communists were clearly gaining ground in South Vietnam and they seemed set to take control of the country unless the US massively increased its military support. On 2 August, the USS Maddox clashed with North Vietnamese torpedo boats in the Gulf of Tonkin near North Vietnam's coast. President Lyndon B. Johnson used the incident to gain Congressional authorization "to take all necessary steps, including the use of armed forces" to assist South Vietnam.
Immediate retaliatory air strikes against North Vietnamese ports and their naval facilities led in March 1965 to Operation Rolling Thunder, a bombing campaign that aimed to destroy North Vietnam's will to fight, by attacking its transport network, air defenses, and industrial base. The first US Marines came ashore in South Vietnam in March to protect the airbases used in Rolling Thunder. The first army ground troops - US 173rd Airborne Brigade - arrived in May. Troop numbers steadily rose to a peak of 530,000 in 1969. Further units - from Australia, New Zealand, the Philippines, South Korea, and Thailand - joined them.
Ruling out an invasion of North Vietnam as too costly and risking a confrontation with China and the Soviet Union, the US preferred to use its massive firepower to mount search-and-destroy missions against communist-controlled areas in South Vietnam, while bombing the north. South Vietnamese troops were sidelined in this conflict, as their morale was low and leadership poor. In contrast, both the North Vietnamese Army and the Viet Cong were disciplined fighters, supplied with weapons brought down the Ho Chi Minh and Sihanouk trails through neutral Cambodia and Laos. They used local knowledge and support to surprise the Americans, before melting away into the jungle. Their sniping skills and use of booby traps proved effective against the US troops, unused to guerrilla warfare.
The Tet Offensive
In mid-1967 General William Westmoreland, US commander in Vietnam, saw "light at the end of the tunnel" and hoped American soldiers could withdraw within two years. Events proved him wrong in January 1968, when the Viet Cong launched the Tet Offensive. The offensive struck targets across South Vietnam, aiming to incite a popular uprising. The Viet Cong even managed to attack the US embassy in the South's capital, Saigon.
Although, in the end, the Communist forces suffered severe casualties, the offensive had a huge psychological impact in the US. Public opinion that once supported the war believed it unwinnable. Protests grew across the United States demanding that the troops come home. The rising death toll - more than 14,000 in 1968 alone - added to the anger. In March the increasingly unpopular Johnson announced that he would not seek re-election and would seek peace talks with North Vietnam. Talks opened in Paris in May.
The US administration of Richard Nixon, elected in November 1968, introduced a policy of "Vietnamization", aimed at building up the strength and effectiveness of the South Vietnamese forces while the US troops pulled out with some dignity intact. At the same time, Nixon expanded the bombing campaign against Viet Cong bases and supply trails in Laos and Cambodia. US and South Vietnamese forces then briefly invaded Cambodia in 1970, hoping to block the supply routes. None of these measures were successful, for at Easter 1972 the North Vietnamese Army launched a full-scale invasion of the south with Soviet-supplied tanks and heavy artillery.
The attack was initially successful, giving North Vietnam control of large areas of the south, but was turned back by July. The following month, the last US combat division left Vietnam. Bombing raids against the north ceased in late December. In January 1973, the United States and North Vietnam signed the Paris Peace Accords and agreed a ceasefire. The US troops left the country a fortnight later.
The Paris ceasefire agreement provided for talks between North and South Vietnam on the future of the country, but the hostilities continued after the Americans had left.
In March 1975, North Vietnam finally overwhelmed the south, capturing Saigon in April and bringing an end to the war.
In 1975 Khmer Rouge guerrillas seized control of Cambodia and implemented a revolutionary restructuring of its society; over one million Cambodians were murdered in the process. Frontier disputes with Vietnam led to a conflict in 1978. Vietnam invaded Cambodia in 1979 and installed a pro-Vietnamese government.
War with China
North Vietnam had support from both the Soviet Union and China during its war with the United States, but turned more towards the USSR in 1978. The Vietnamese invasion of Cambodia led the Chinese to invade Vietnam briefly in February 1979.