1979 Vietnamese Take Phnom Penh
In January 1979 Vietnamese troops captured Phnom Penh, in attempt to overthrow the government of Pol Pot. In response, the Chinese invaded North Vietnam..
The Khmer Rouge, led by Pol Pot, seized power in Cambodia in 1975 and ruled until 1979. During their regime, they enacted radical policies aimed at creating an agrarian-based communist society, which led to mass starvation, forced labor, and genocide. It's estimated that nearly 2 million Cambodians died during this period, known as the Cambodian Genocide.
Vietnam, after unifying under the communist banner in 1975 post the Vietnam War, had a strained relationship with the Khmer Rouge due to ideological differences and territorial disputes. The tensions led to various border skirmishes throughout the late 1970s.
By late 1978, the situation had escalated and Vietnam launched a full-scale invasion of Cambodia, capturing the capital, Phnom Penh, in January 1979. This led to the fall of the Khmer Rouge regime, with Pol Pot and his associates retreating to the Thai border where they continued an insurgency campaign for another two decades.
Chinese Invasion of North Vietnam (Sino-Vietnamese War): China's response to Vietnam's invasion of Cambodia was largely motivated by geopolitical considerations. China was an ally of the Khmer Rouge and saw the Vietnamese invasion as a threat to the balance of power in Southeast Asia. More so, Vietnam had close ties with the Soviet Union, China's geopolitical rival during the Cold War era.
In February 1979, shortly after the fall of the Khmer Rouge, China launched an invasion of Vietnam, initiating the Sino-Vietnamese War. The Chinese described this as a "punitive expedition" and their goal was not to conquer Vietnam but to "teach Vietnam a lesson," dissuade them from further expansion and undermine their military capacity.
The war was short but bloody, lasting less than a month, with both sides claiming victory. China withdrew its troops from Vietnam, while Vietnam continued to occupy Cambodia until 1989, establishing the People's Republic of Kampuchea, a pro-Vietnamese government, in the meantime.
Despite the military actions ending, the two countries only normalized their diplomatic relations in 1991, more than a decade after the war.