The Sino?ietnamese War was a brief but bloody border war fought in 1979 between the People's Republic of China (PRC) and the Socialist Republic of Vietnam.

The PRC launched the offensive in response to Vietnam's 1978 invasion and occupation of Cambodia, which ended the reign of the PRC-backed Khmer Rouge.

The Chinese invaded Northern Vietnam and captured some of the northernmost cities in Vietnam. On March 6 China declared that the gate to Hanoi was open and that their punitive mission had been achieved and retreated back to China.

Both China and Vietnam claimed victory in the last of the Indochina Wars of the twentieth century