Vietnam War

The Vietnam War, also known as the Second Indochina War, and in Vietnam as the Resistance War Against America or simply the American War, was a conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the Fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vietnam and the government of South Vietnam. The North Vietnamese army was supported by the Soviet Union, China, and other communist allies; the South Vietnamese army was supported by the United States, South Korea, the Philippines, Australia, Thailand and other anti-communist allies. The war is considered a Cold War-era proxy war by some US perspectives. The war would last approximately 19 years and would also form the Laotian Civil War as well as the Cambodian Civil War, which resulted in all 3 countries becoming communist states in 1975.

There are several competing views on the conflict. Some on the North Vietnamese and Viet Cong side view the struggle against U.S. forces as a colonial war and a continuation of the First Indochina War against forces from France and later on the United States, especially in light of the failed 1954 Geneva Conference calls for elections. Other interpretations of the North Vietnamese side include viewing it as a civil war, especially in the early and later phases following the U.S. interlude between 1965 and 1970 as well as a war of liberation. In the perspective of some, the Provisional Revolutionary Government of the Republic of South Vietnam, the successor to the Việt Cộng, was motivated in part by significant social changes in the aftermath of World War II Vietnam, and had initially seen it as a revolutionary war supported by Hanoi. The pro-government side in South Vietnam viewed it as a civil war, a defensive war against communism, or were motivated to fight to defend their homes and families. The U.S. government viewed its involvement in the war as a way to prevent a communist takeover of South Vietnam. This was part of the domino theory of a wider containment policy, with the stated aim of stopping the spread of communism.

Beginning in 1950, American military advisors arrived in what was then French Indochina. Most of the funding for the French war effort was provided by the U.S. or FNL (the National Liberation Front), a South Vietnamese communist common front aided by the North, fought a guerrilla war against anti-communist forces in the region, while the People's Army of Vietnam, also known as the North Vietnamese Army (NVA), engaged in more conventional warfare, and had launched armed struggles from 1959 onward. U.S. involvement escalated in 1960 under President John F. Kennedy, with troop levels gradually surging under the Military Assistance Advisory Group program from just under a thousand in 1959 to 16,000 in 1963.

By 1964 there were 23,000 U.S. troops in Vietnam, but this escalated further following the 1964 Gulf of Tonkin incident, in which a U.S. destroyer was alleged to have clashed with North Vietnamese fast attack craft. In response the Gulf of Tonkin Resolution gave Lyndon B. Johnson authorization to increase U.S. military presence, deploying ground combat units for the first time and increasing troop levels to 184,000. Every year onward there was significant build-up despite little progress, with Robert McNamara, one of the principal architects of the war, beginning to express doubts of victory by the end of 1966. 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. conducted a large-scale strategic bombing campaign against North Vietnam. Following the Tet Offensive, U.S. forces began withdrawal under the Vietnamization phase; the Army of the Republic of Vietnam unconventional and conventional capabilities increased following a period of neglect and became modeled on heavy fire-power focused doctrines like US forces. Operations crossed international borders: bordering areas of Laos and Cambodia were used by North Vietnam as supply routes and were heavily bombed by U.S. forces.

Gradual withdrawal of U.S. ground forces began as part of "Vietnamization", which aimed to end American involvement in the war while transferring the task of fighting the communists to the South Vietnamese themselves and begun the task of modernizing their armed forces. Morale declined significantly among U.S. forces during the wind-down period and incidents of fragging, drug-use and insubordination increased with General Creighton Abrams remarking "I need to get this army home to save it". From 1969 onwards the military actions of the Việt Cộng insurgency decreased as the role and engagement of the NVA grew. Initially fielding less conventional and poorer weaponry, from 1970 onward the People's Army of Vietnam and its branch People's Liberation Armed Forces of South Vietnam had increasingly became mechanised and armoured, capable of modernised combined arms and mobile warfare and begun to widely deploy newer, untested weapons. These two sides would see significant, rapid changes throughout its lifetime from their original post-colonial armies, and by mid-1970s the ARVN became the fourth largest army with the PAVN became the fifth largest army in the world in two countries with a population of roughly 20 million each.

Despite the Paris Peace Accord, which was signed by all parties in January 1973, the fighting continued as both Saigon and Hanoi attempted to take territory before and after the accord; the ceasefire was broken just days after its signing. In the U.S. and the Western world, a large anti-Vietnam War movement developed as part of a larger counterculture, the largest such anti-war movement up to that point in history. The war changed the dynamics between the Eastern and Western Blocs, altered North–South relations, and significantly influenced the political landscape in the United States. Across much of Western Europe and the U.S., ground-force intervention spurred the rise of transnational political movements and campaigning.

Direct U.S. military involvement ended on 15 August 1973 as a result of the Case–Church Amendment passed by the U.S. Congress. The fall of Saigon by the North Vietnamese 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 966,000 to 3.8 million. Some 275,000–310,000 Cambodians, 20,000–62,000 Laotians, and 58,220 U.S. service members also died in the conflict, and a further 1,626 remain missing in action. The Sino-Soviet split re-emerged following the lull during the Vietnam War and ties between the DRV and its Cambodian allies in the Royal Government of the National Union of Kampuchea, the newly-formed Democratic Kampuchea begun almost immediately in a series of border raids by the Khmer Rouge and erupted into the Cambodian–Vietnamese War, with Chinese forces directly intervening in the Sino-Vietnamese War. The end of the war and resumption of the Third Indochina War would precipitate the Vietnamese boat people and the bigger Indochina refugee crisis, which saw an estimated 250,000 people perish at sea.