The Vietnam War (), also known as the Second Indochina War, was a conflict 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 South Vietnam. North Vietnam was supported by the Soviet Union, China, and other communist allies; South Vietnam was supported by the United States, South Korea, the Philippines, Australia, Thailand, and other anti-communist allies. The war, considered a Cold War-era proxy war by some, lasted almost 20 years, with direct U.S. involvement ending in 1973, and included the Laotian Civil War and the Cambodian Civil War, which ended with all three countries becoming communist in 1975.