The Vietnamese Communists won their war for independence and unification in 1975, but they were not satisfied. Immediately after the end of hostilities with South Vietnam, the newly formed Socialist Republic of Vietnam turned on its erstwhile ally, Democratic Kampuchea, controlled by the communist Khmer Rouge. 1 During the Vietnam War, North Vietnam had allied with the Khmer Rouge to kick out the U.S. and eventually overcome the South Vietnamese government. When North Vietnam won and unified Vietnam, the Khmer Rouge consolidated their power in Cambodia and renamed it Democratic Kampuchea. It was anything but democratic; the Khmer Rouge set up “re-education” camps for political prisoners and massacred as many as three million people. But there was bad blood between the Vietnamese Communists and the Khmer Rouge, and they began fighting along the border areas between Vietnam and Cambodia. The Vietnamese–Cambodian War lasted from 1975 to 1978, and was marked by small-scale action between the two sides for control over the former Cambodia.