Undated image of a B-52 bomber dropping conventional bombs over Vietnam. The Vietnam War was a Cold War-era proxy war that occurred in Vietnam, Laos, and Cambodia from November 1955 to the fall of Saigon on April 30, 1975. As the war continued, 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. The U.S. government viewed its involvement in the war as a way to prevent a Communist takeover of South Vietnam. Direct U.S. military involvement ended in 1973. The capture of Saigon by the North Vietnamese Army in April 1975 marked the end of the war, and North and South Vietnam were reunified the following year.