As Lemkin noted, war and genocide are almost always connected. The Ottomans killed more than 1 million Armenians during World War I, and the Germans exterminated 6 million Jews and 5 million Poles, Roma, homosexuals, political opponents, and others during World War II. Iraq later targeted its Kurdish minority during the Iran-Iraq war; Bosnian Serbs set out to destroy Muslims and Croats during a Balkan civil war; and Rwandan Hutu nationalists exterminated some 800,000 Tutsi while the Rwandan army also fought a more conventional civil war against a Tutsi rebel force. History is replete with conflicts between regular armed forces that unleash and fuel the passions that give rise to campaigns to eliminate certain “undesirables.”War legitimates such extreme violence that it can make aggrieved or opportunistic citizens feel licensed to target their neighbors. For outsiders, war between armies can also mask genocide, making it initially difficult to discern eliminationist campaigns against civilians and inviting customary diplomatic efforts. In Cambodia two wars preceded the genocide: the U.S. war in Vietnam and a civil war in Cambodia. These wars earned the Khmer Rouge converts to their cause, and they also helped obscure the savagery of the new Communist movement.
American reticence in the face of the Cambodian horrors between 1975 and 1979 is tightly intertwined with the U.S. role in the region in the previous decade. The American war in Vietnam was intended to prevent South Vietnam, another “domino,” from becoming Communist. The U.S. troop presence in Vietnam peaked at 550,000 in early 1968. The same year the stunning Vietcong Tet offensive against all the main U.S. bases in South Vietnam left some 4,000 Americans dead and strengthened American domestic opposition to the war.6 This restiveness on the home front only intensified with coverage of the 1968 My Lai massacre and the outrage over American use of defoliants and napalm.7 American lives were being lost in Vietnam, American honor was being soiled, and North Vietnam was winning the war.
Richard Nixon became president in 1969. Although he had pledged to end the Vietnam War, Nixon in fact expanded it into Cambodia. Because North Vietnamese units were taking sanctuary in neighboring Cambodia, the country became a “sideshow” of some importance to the new administration. The United States invested heavily in the idea that the two bands of Communists, the Cambodians and the Vietnamese, were united. In March 1969 Nixon ordered American B-52s to begin bombing Cambodia.8 Code-named “Operation Breakfast” for the setting in which National Security Adviser Henry Kissinger and U.S. military advisers drafted their bombing plans, the mission was kept top secret for fear of domestic protest. When the bombers failed to locate the Communists’ bases, Nixon expanded the mission. He authorized secret attacks on other sanctuaries and followed up Operation Breakfast with further unappetizing missions, named Operations Lunch, Snack, Dinner, Dessert, and Supper. In the first phase of the bombing campaign, which lasted fourteen months and was known as Menu, U.S. bombers flew 3,875 sorties.9
President Nixon did not stop there. In April 1970, frustrated by the elusiveness of the North Vietnamese, he ordered U.S. ground troops to “clean out” North Vietnamese strongholds in Cambodia. Nixon warned, “If, when the chips are down, the world’s most powerful nation—the United States of America—acts like a pitiful, helpless giant, the forces of totalitarianism and anarchy will threaten free nations and free institutions throughout the world.” Some 31,000 American and 43,000 South Vietnamese forces surged into Cambodia, ostensibly to prevent the Communists there from staging “massive attacks” on U.S. troops in Vietnam.10 The invasion, which Nixon insisted was only an “incursion,” had nothing to do with the Cambodians and everything to do with the U.S. war with Vietnam. Defense Secretary James Schlesinger later testified to Congress, “The value of Cambodia’s survival derives from its importance to the survival of South Vietnam.”11
The month before the U.S. ground attack on Cambodia, the United States had welcomed a coup by the pro-American prime minister, Lon Nol, against Cambodia’s longtime ruler, Prince Norodom Sihanouk. Sihanouk, the father of independent Cambodia, had acquired the aura of an ancient Angkor deva-raj, or god-king, since he had assumed the throne in 1941. A bon vivant, Sihanouk was a movie director, a gourmet, and a womanizer, as well as a popular head of state. But he had alienated the United States by striking up a friendship with China, America’s foe at the time. He had also irritated President Nixon by trying to keep Cambodia neutral in the U.S. war with Vietnam. U.S. officials believed Lon Nol would be far more malleable to American designs.
But the United States had backed a loser. Lon Nol was pro-American, but like many U.S.-sponsored dictators of the period, he was also corrupt, repressive, and incompetent. He secluded himself in his villa in the Cambodian capital of Phnom Penh and remained woefully out of touch with the affairs of his state. He depended on the mystical advice of a visionary monk named Mam Prum Moni, or “Great Intellectual of Pure Glory.”The only assertive moves Lon Nol made were those designed to increase his own power. He stripped citizens of basic freedoms, suspended parliament, and announced in October 1971 that it was time to end “the sterile game of outmoded liberal democracy.” In 1972 he declared himself president, prime minister, defense minister, and marshal of the armed forces. The United States cared only that Lon Nol was a staunch anti-Communist. The United States spent some $1.85 billion between 1970 and 1975 propping up his regime—evidence, in President Nixon’s words, of “the Nixon Doctrine in its purest form.”12
The U.S. ground invasion of April 1970 occurred at the beginning of Cambodia’s five-year civil war, a merciless war that the genocidal Khmer Rouge would win. On one side were Lon Nol and the United States. On the other side stood the Vietnamese Communists and the small, mysterious group of radical Cambodian Communist revolutionaries. The leaders of the Khmer Rouge, or Red Khmer, had been educated in Paris, studied Maoist thought, and received extensive political and military support from China. They were youths who had been driven to Communist resistance out of frustration with Prince Sihanouk’s earlier, authoritarian rule. Under the leadership of Saloth Sar, who later assumed the pseudonym Pol Pot, they had left Cambodia’s cities in the 1960s to plot revolution from the Cambodian and Vietnamese countryside.13 It had been Sihanouk’s tyranny that drove them to arms, but when Lon Nol seized power in the 1970 coup, the KR began fighting Lon Nol’s government forces instead and made their former nemesis Prince Sihanouk the figurehead leader of an unlikely coalition. This earned them support from the millions of Cambodians who trusted Sihanouk, the likable man who had brought them independence. Although doubts emerged in 1973 and 1974 about whether the more moderate Sihanouk spoke for the KR, Cambodians trusted his judgment. “I do not like the Khmer Rouge and they probably do not like me,” the prince said in 1973. “But they are pure patriots…Though I am a Buddhist, I prefer a red Cambodia which is honest and patriotic than a Buddhist Cambodia under Lon Nol, which is corrupt and a puppet of the Americans.”14
Even backed by the United States, the Lon Nol regime did not stand much of a chance in battle. Its forces were equipped for parades, not warfare.15 In 1972 Lon Nol famously had airplanes sprinkle blessed sand around Phnom Penh’s perimeters to ward off his ungodly Communist enemies. Lon Nol’s officers exaggerated Cambodian army troop strength, listing phantom troops and using U.S. aid to pad their pockets, stuff foreign bank accounts, and build themselves glamorous homes. Regular army soldiers, by contrast, frequently went unpaid and deserted. And though the Cambodian army enjoyed a huge numerical edge over the rebels, many were unenthusiastic about fighting on behalf of Lon Nol. Those who did fight were dependent on U.S. bombing and, later, U.S. military aid.
U.S. interest in Cambodia during the civil war was completely derivative of U.S. designs on Vietnam. So when U.S. troops withdrew from Vietnam in January 1973, the bombing of Cambodia became harder to justify. In August 1973 Congress finally stepped in to ban the air campaign. President Nixon was furious. He blamed Congress for weakening regional security and “raising doubts in the mind of both friends and adversaries” about U.S. “resolve.” All told, between March 1969 and August 1973, U.S. planes dropped 540,000 tons of bombs onto the Cambodian countryside.16 The United States continued to supply military and financial assistance to Lon Nol, warning that a “bloodbath” would ensue if the KR were allowed to triumph.
The U.S. B-52 raids killed tens of thousands of civilians.17 Villagers who happened to be away from home returned to find nothing but dust and mud mixed with seared