The Vietnam War was fought from November 1955 to April 1975 across Vietnam, Laos, and Cambodia. South Vietnam and its American and anti-communist allies faced North Vietnam and the Viet Cong, backed by the Soviet Union and China. Fierce guerrilla warfare defined the conflict, and US search-and-destroy operations pushed deep into the Vietnamese jungle. The North Vietnamese capture of Saigon in April 1975 ended the war and unified the country under communist rule.