The Vietnam War (Vietnamese: Chiến tranh Việt Nam) was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of South Vietnam, supported by the United States and other anti-communist countries. The Viet Cong (also known as the National Liberation Front, or NLF), a lightly armed South Vietnamese communist common front directed by the North, largely fought a guerrilla war against anti-communist forces in the region. The Vietnam People’s Army (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 U.S. government viewed involvement in the war as a way to prevent a communist takeover of South Vietnam as part of their wider strategy of containment. The North Vietnamese government and Viet Cong viewed the conflict as a colonial war, fought initially against France, backed by the U.S., and later against South Vietnam, which it regarded as a U.S. puppet state. American military advisors arrived in what was then French Indochina beginning in 1950. U.S. involvement escalated in the early 1960s, with troop levels tripling in 1961 and tripling again in 1962. U.S. combat units were deployed beginning in 1965. Operations spanned international borders, with Laos and Cambodia heavily bombed. American involvement in the war peaked in 1968, at the time of the Tet Offensive. After this, U.S. ground forces were gradually withdrawn as part of a policy known as Vietnamization. Despite the Paris Peace Accords, signed by all parties in January 1973, fighting continued.
U.S. military involvement ended on 15 August 1973 as a result of the Case–Church Amendment passed by the U.S. Congress. The capture of Saigon by the Vietnam People’s 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 fewer than one million to more than three million. Some 200,000–300,000 Cambodians, 20,000–200,000 Laotians and 58,220 U.S. service members also died in the conflict.