The Cambodian-Vietnamese War refers a series of conflicts between the two countries, culminating in the Vietnamese invasion and subsequent occupation of Cambodia and the removal of the Khmer Rouge regime from power.The conflict, apart from highlighting the traditional animosities between Vietnam and Cambodia, also reveals how deeply the Sino-Soviet split has broken open the communist movement of this time.

The Communist Party of Vietnam had sided with (after a period of ambivalence) the Soviet Union whereas the Communist Party of Kampuchea remains loyal with the People's Republic of China.