Vietnam War

The Vietnam War was a military conflict that occurred in Vietnam, Laos, and Cambodia from 1959 to 30 April 1975. The war was fought between North Vietnam, supported by its communist allies, and the government of South Vietnam, supported by the United States and other nations.

The Viet Cong, a lightly armed South Vietnamese pro communist-controlled common front, largely fought a guerrilla war against anti-communist forces in the region. The 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 United States entered the war to prevent a communist takeover of South Vietnam as part of their wider strategy of containment. Military advisors arrived beginning in 1950. U.S. involvement escalated in the early 1960s and combat units were deployed beginning in 1965. Involvement peaked in 1968 at the time of the Tet Offensive.

After this, U.S. ground forces were withdrawn as part of a policy called Vietnamization. Despite Paris Peace Accords, signed by all parties in January 1973, fighting continued.

The Case-Church Amendment, passed by the U.S. Congress in response to the anti-war movement, prohibited direct U.S. military involvement after August 15, 1973. U.S. military and economic aid continued until 1975. The capture of Saigon by North Vietnamese army, in April 1975, marked the end of Vietnam War. North and South Vietnam were reunified the following year.

Aftermath
The war exacted a huge human cost in terms of fatalities, including 3 to 4 million Vietnamese from both sides, 1.5 to 2 million Laotians and Cambodians, and 58,159 U.S. soldiers.

Events in Southeast Asia
Phnom Penh, the capital of Cambodia, fell to followers of the Communist Party of Kampuchea, a false-socialist organization commonly known as the Khmer Rouge, on 17 April 1975. Over the next four years, the Khmer Rouge enacted a racial 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 false-socialist 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.

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.

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.