Editor’s Note: This is Part I of a three part series.
I recently had the good fortune to spend some time in Cambodia. Part of the lure was the country’s magnificent history, embodied best in the medieval Khmer Empire. Its more recent history is sadly, far darker. During a stay in Phnom Penh, I visited sites like the Tuol Sleng Genocide Museum and the killing fields at Choeung Ek; at the same time, I worked my way through the historiography of this most horrific of modern events. I was surprised by one repeated refrain among historians and journalists: that the Cambodian genocide had little to do with the ideology of the ruling Communist Party of Kampuchea (the CPK, also known as the Khmer Rouge). Instead, journalists and scholars sought to pin the origins of the Cambodian genocide on factors ranging from the US military’s intervention in Cambodia’s civil war to unique Cambodian cultural attitudes. Do these arguments bear the weight of historical scrutiny?
In December 1978, the People’s Army of Vietnam invaded Cambodia. Years of increasingly violent border clashes, a swelling refugee crisis and collapsing relations with China – who backed Cambodia – all drove the Communist Vietnamese government into open war. To their surprise, Cambodian forces evaporated as the Vietnamese crossed the border. Within a month, the Vietnamese Army occupied Phnom Penh and installed a puppet regime. As the new government reached the capital alongside their Vietnamese allies, they were shocked to find a nearly empty city. One of the few signs of life was a huge prison and torture complex located in the city center in a former elementary school. Exploration around the countryside revealed a vast network of killing fields. Even the Communist Vietnamese, responsible for more than 1.7 million “political executions” of their own people between 1945 and 1975, found the death toll staggering.
The Khmer Rouge (literally, Red Cambodians), had ruled the country for less than four years. During that time, it was responsible for horrific barbarism against its own people, killing somewhere between 1.7 and 3.4 million people in a country of less than eight million. Among those targeted were all urban dwellers, prosperous peasants, the literate, and even the working class. Symbols of modernity – schools, hospitals, cars, radios, televisions, churches – were attacked, destroyed or burned to the ground. As the full extent of the horror became known, the international world sought an answer as to how such an event could occur.
Many of the first American journalists to cover Cambodia, fresh from the experience of Vietnam, argued that the United States was responsible, having destabilized the country and radicalized the Khmer Rouge. The US had begun bombing Cambodia secretly in 1969 to interdict supplies flowing down the Ho Chi Minh trail to the Viet Cong. The scale of US bombing was intense: Cambodia received more than three times the total tonnage of all bombs dropped on Japan from 1941 to 1945. New York Times correspondent Sydney Schanberg wrote that the Khmer Rouge “… would point… at the bombs falling from B-52s as something they had to oppose if they were going to have freedom. And it became a recruiting tool until they grew to a fierce, indefatigable guerrilla army.”
However, blaming US attempts to eliminate the Khmer Rouge on the Khmer Rouge’s policy of genocide is somewhat problematic. In the words of Philip Short, “it would be wrong to suggest that the intensity of the bombing brutalized Cambodians and thereby contributed to the nature of the regime which Pol and his colleagues installed.” Vietnam suffered far worse bombings than Cambodia, but never developed the sort of pathological totalitarianism that developed in Cambodia. Second, it is clear from source material that has since become available that the decision to commit mass murder against much of Cambodia’s civilian population came from Pol Pot and his circle, who did not experience the bombings. They were motivated by long-held ideas about the future of their country, not American attacks. Finally, fighting had raged off and on for twenty years before the bombing began, suggesting the violence of the Khmer Rouge predated the American intervention. As Short concludes, “the bombing may have helped create a climate conducive to extremism. But the ground war would have done that anyways.” The American bombing of Cambodia was tragic, shortsighted, and strategically inept, but ultimately, it was not the primary catalyst of the later, greater tragedy.
 Philip Short, Pol Pot: The History of a Nightmare (London: John Murray Publishers, 2004), p. 397.
 R.J. Rummel, “Chapter Six: Vietnam” in Statistics of Democide: Genocide and Mass Murder since 1900 (Charlottesville, VA: Center for National Security Law, 1997), https://www.hawaii.edu/powerkills/SOD.TAB6.1A.GIF.
 The lower figure is from Ben Kiernan’s The Pol Pot Regime: Race, Power and Genocide in Cambodia under the Khmer Rouge, 1975-1979 (New Haven: Yale University Press, 1996), p. 458. A range of other figures are discussed throughout the literature; a good summary can be found here. Given that more than 1.4 million bodies have been unearthed thus far, the final figure seems to have been at least 2 million.
 This claim is partially made by a Finnish UN Commission in Kampuchea: Decade of the Genocide. Report of a Finnish Inquiry Commission, Edited by Kimmo Kiljunen (London: Zed Books, 1984), p. 8, p. 71. It was reiterated, in a manner blaming both US and Soviet policymakers in Michael Haas, Genocide by Proxy: Cambodian Pawn on a Superpower Chessboard (Westport, CT: Praeger, 1991).
 Short, pp. 216-218.
 See, for instance, the Yale Cambodian Genocide Databases. http://gsp.yale.edu/cambodian-genocide-databases-cgdb
 Short, p. 218.