The Vietnam War , also known as the Second Indochina War, and also known in Vietnam as Resistance War Against America or simply the American War, was a Cold War-era proxy war 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 (1946–54) and was fought between North Vietnam—supported by the Soviet Union, China and other communist allies—and the government of South Vietnam—supported by the United States and other anti-communist allies.The Viet Cong, a South Vietnamese communist common front aided by the North, fought a guerrilla war against anti-communist forces in the region. The People's Army of vietnam engaged in a more conventional war, at times committing large units to battle.As the war wore on, the part of the Viet Cong in the fighting decreased as the role of the NVA grew. 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. In the course of the war, the U.S. conducted a large-scale strategic bombing campaign against North Vietnam, and over time the North Vietnamese airspace became the most heavily defended in the world.The U.S. government viewed American involvement in the war as a way to prevent a Communist takeover of South Vietnam. This was part of a wider containment strategy, with the stated aim of stopping the spread of communism.