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 April 30, 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 19 years, with direct U.S. involvement ending in 1973, and included the Laotian Civil War and the Cambodian Civil War, resulting in all three countries becoming communist in 1975.