The Khmer Rouge Capture of Phnom Penh on 17 April 1975 That Initiated the Cambodian Genocide

The Khmer Rouge — formally the Communist Party of Kampuchea under General Secretary Pol Pot (born Saloth Sar) — had been waging civil war against the Cambodian government of Lon Nol since 1970. US air operations against Cambodian Communist forces across 1969-1973 had dropped approximately 540,000 tonnes of bombs, contributing to a rural radicalization that the Khmer Rouge harnessed.

By April 1975 the Lon Nol government controlled little beyond Phnom Penh. The American Ambassador John Gunther Dean evacuated by helicopter on 12 April 1975 under Operation Eagle Pull, lifting 276 evacuees from a soccer field near the embassy.

17 April 1975

The Khmer Rouge entered Phnom Penh on 17 April 1975. The young soldiers in black pyjamas were initially welcomed by the city population that had assumed the war was simply ending. Within hours the Khmer Rouge began ordering the complete evacuation of the city’s approximately 2 million residents — including the city’s hospitals — into the countryside under the pretext of an imminent American bombing raid.

The evacuation lasted approximately three days. Approximately 20,000 Cambodians died on the roads — patients pushed out of hospitals in their beds, the elderly, infants. The Khmer Rouge ideology was a agrarian primitivism — Pol Pot’s vision was a return to a mythical pre-colonial agrarian society in which the cities and the educated classes were abolished.

Democratic Kampuchea

The Khmer Rouge state — renamed Democratic Kampuchea in 1976 — operated on the following principles:

— Year Zero — the abolition of all pre-1975 institutions, calendars, religions, currencies, postal services, schools (the calendar was reset to Year Zero on 17 April 1975) — Agrarian forced labour — the evacuated city populations were resettled as “New People” in rural cooperatives. Daily food rations were approximately 250-500 grams of rice — below subsistence — The Four Pillars that defined a counter-revolutionary: city dwellers, educated people, ethnic minorities, Buddhist monks. All four categories were progressively eliminated — No families — children were separated from parents into work brigades; marriage was reorganized by Party assignment

The killing

The deaths across the Khmer Rouge period 1975-1979 are attributed approximately to:

— Execution: approximately 700,000 — Starvation and disease: approximately 700,000 — Forced labour deaths: approximately 300,000 — Total deaths: approximately 1.7 million from a pre-1975 population of approximately 7.9 million

The principal execution facility was S-21 (Tuol Sleng) in central Phnom Penh — a former high school converted by the Khmer Rouge into an interrogation and torture centre under commandant Kaing Guek Eav (“Comrade Duch”). Approximately 14,000 prisoners passed through S-21 across 1975-1979; the documented survivors number 12. Prisoners were photographed on arrival; the photograph archive of approximately 6,000 surviving portraits is among the principal documentary records of the genocide.

Executions were carried out at Choeung Ek — the “Killing Fields” approximately 17 km south of Phnom Penh. Ammunition was preserved by killing with farm implements — hammers, machetes, sharpened bamboo. Skull fragments and clothing remain partially exposed in the field today.

The end

Vietnamese-Cambodian border skirmishes across 1977-1978 escalated to full Vietnamese invasion on 25 December 1978. Phnom Penh fell on 7 January 1979. Pol Pot and the Khmer Rouge leadership fled to the Thai border, where they continued a guerrilla insurgency until 1998 under Chinese and (clandestinely) US support designed to oppose the Vietnamese-installed government of Heng Samrin.

Pol Pot died of a heart attack on 15 April 1998 in a hut on the Thai-Cambodian border, having faced no judicial accountability.

The Extraordinary Chambers in the Courts of Cambodia — a UN-backed tribunal — convened in 2006. Three senior Khmer Rouge officials were convicted:

— Duch (the S-21 commandant) — convicted in 2010, sentenced to life — Nuon Chea (Brother Number Two) — convicted in 2014, life imprisonment, died 2019 — Khieu Samphan (head of state) — convicted in 2014, life imprisonment

The Cambodian Communist Party member who survived a Khmer Rouge attempt to purge him in 1978 — Hun Sen — became prime minister under the Vietnamese occupation in 1985 and continued in office until 2023 — among the longest tenures of any modern head of government.