The Vietnam War grew out of Vietnam's long history as a French colony. After World War 2, Vietnam was divided into a communist North and democratic South. The US backed South Vietnam in an attempt to contain communism, believing that if South Vietnam fell, other countries would too. Despite US bombing campaigns and search/destroy missions that caused massive casualties, the Viet Cong waged a successful guerrilla war. US involvement became increasingly unpopular as the war dragged on. Ultimately, the US was unable to stop the communist takeover and North Vietnam reunified the country in 1975.