Cambodian–Vietnamese War

Armed conflict of 1978-1989 between Democratic Kampuchea and the Socialist Republic of Vietnam, part of the Third Indochina War. After repeated Khmer Rouge border attacks, including the Ba Chuc massacre of over 3,000 Vietnamese civilians in April 1978, Vietnam launched a full-scale invasion on 25 December 1978, capturing Phnom Penh within two weeks and toppling the Khmer Rouge, ending the Cambodian genocide. Vietnam installed a new Cambodian government but was left diplomatically isolated; its troops withdrew completely in September 1989, and the 1991 Paris Peace Agreements opened reconciliation.