Conflict with Cambodia

Although the communists had succeeded in taking power over all of Vietnam, real peace was not yet present in Indochina. The Pol Pot regime in Cambodia carried out a massive program of relocating people from the cities to the countryside, a scheme that resulted in hundreds of thousands of deaths.

Eventually the North Vietnamese became afraid of Cambodia's disorder and sought to control Cambodia through military action. The North Vietnamese invaded Cambodia and drove the Pol Pot regime into near-exile on the Thailand-Cambodia border.

This confirmed that, at least in Southeast Asia, communist governments were as likely to oppose one another as to be allies.

By 1979 China, North Vietnam's erstwhile communist ally, decided that they had had enough of the increased Vietnamese control in Cambodia and attacked Vietnam. The battle-hardened Vietnamese army exacted more than twenty thousand Chinese casualties and stopped the much larger but less effective Chinese forces only a few miles inside the Vietnamese border. This was a major setback for China's prestige. After that, the Vietnamese exercised political control in most of Cambodia, ending the massive killing directed by Pol Pot.

Pol Pot survived for many years fighting a guerrilla war against the Vietnamese using Chinese weapons and supplies shipped through neighboring Thailand. Ultimately, the Khmer Rouge split, and other neutralist forces led by former Cambodian leader Prince Sihanouk reentered Cambodian politics as the result of several attempted negotiated settlements.

Although the Vietnamese withdrew their troops in 1989, they left the government that they had established in power. This government, under the leadership of Prime Minister Hun Sen, a former Vietnamese ally, shared power for a time with other factions. By the late 1990's, however, Hun Sen had managed to push out most of the other groups and he was the acknowledged leader of the country by the first decade of the twenty-first century. There is no indication that Hun Sen was still in league with the Vietnamese, but Cambodia had largely ceased to be a threat to Vietnamese interests.