The Vietnam War was fought in part by the US.
The Vietnam War ( Chiến tranh Việt Nam ) , also known as the Second Indochina War , and known in Vietnam as Resistance War Against America ( Kháng chiến chống Mỹ ) or simply the American War , was a war that occurred 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 the government of South Vietnam . The North Vietnamese army was supported by the Soviet Union , China and other communist allies and the South Vietnamese army was supported by the United States , South Korea , Australia , Thailand and other anti-communist allies . The U.S. government viewed its involvement in the war as a way to prevent a communist takeover of South Vietnam . Regular U.S. combat units were deployed beginning in 1965 .