Cambodia under Pol Pot's leadership

In 1969 the United States carpet-bombed suspected communist base camps in Cambodia, killing thousands of civilians and dragging the country unwillingly into the US-Vietnam conflict. American and south Vietnamese troops invaded the country in 1970 to eradicate Vietnamese communist forces but were unsuccessful; they did manage, however, to push Cambodia's leftist guerillas (the Khmer Rouge) further into the country's interior. Savage fighting soon engulfed the entire country, with Phnom Penh falling to the Khmer Rouge in April 1975.

Over the next four years the Khmer Rouge, under Pol Pot's leadership, systematically killed an estimated two million Cambodians (targeting the educated in particular) in a brutal bid to turn Cambodia into a Maoist, peasant-dominated agrarian cooperative. Currency was abolished, postal services were halted, the population became a work force of slave labourers and the country was almost entirely cut off from the outside world. Responding to recurring armed incursions into their border provinces, Vietnam invaded Cambodia in 1978, forcing the Khmer Rouge to flee to the relative sanctuary of the jungles along the Thai border. From there, they conducted a guerilla war against the Vietnamese-backed government throughout the late 1970s and 80s.

In mid-1993, UN-administered elections led to a new constitution and the reinstatement of Norodom Sihanouk as king. The Khmer Rouge boycotted the elections, rejected peace talks and continued to buy large quantities of arms from the Cambodian military leadership. In the months following the election, a government-sponsored amnesty secured the first defections from Khmer ranks, with more defections occurring from 1994 when the Khmer Rouge was finally outlawed by the Cambodian government.