Of all the myths about the Vietnam War, the most vicious one is the idea that the United States was morally responsible for the atrocities committed after the fall of Cambodia in 1975. The critics charged that the actions we took against North Vietnam's Cambodian sanctuaries, starting with the bombing of Communist bases in 1969, began a series of events that brought the murderous Khmer Rouge to power. This is a total distortion of history and complete perversion of moral judgment.
The myth ran like this: Our secret bombing in 1969 not only slaughtered countless civilians but also pushed the Vietnamese Communist forces deeper into Cambodia and thereby destabilized Sihanouk's neutral government. Our incursions against the sanctuaries in 1970 swept peaceful Cambodia into the war and led the North Vietnamese to give massive aid to their Communist Khmer Rouge allies. Therefore, because American actions set in motion the events that brought the Khmer Rouge to power, the United States was to blame for ensuing holocaust, in which over 2 million Cambodians were killed.
These arguments are wrong on every point. Our bombing caused minimal civilian casualties because the Communists had long before cleared all Cambodians out of their base areas. A Joint Chiefs of Staff memorandum written in April 1969 pointed out that "Cambodians rarely go into areas under de facto control of the [National Liberation Front and North Vietnamese Army]." It added, "Cambodian villages and populated areas are readily identified and can be essentially avoided in conducting preplanned operations into the base areas."
Nor did our bombing destabilize Sihanouk's government. No evidence exists to show that our 1969 air strikes pushed the Vietnamese Communist forces deeper into Cambodia. These forces grew at the time of the bombing, both because a steady stream of new troops was coming down the Ho Chi Minh Trail and because United States and South Vietnamese military sweeps in South Vietnam were pushing more Communist troops into Cambodia. But none of these forces went deeper into Cambodia as a result of the bombing. Communist forces simply dispersed themselves and their supplies more widely along the border with South Vietnam.
Sihanouk was overthrown because of discontent, both among the people and within the government, over his unwillingness to take vigorous steps to expel the Vietnamese Communist forces from the country. Years later Sihanouk admitted as much, saying, "If I lost my Fauteuil presidentiel and my Chamcar Mon Palace in Phnom Penh to Marshal Lon Nol who occupied them for five years, it was because I tremendously helped the Viet Cong and the North Vietnamese."
Our incursions into Cambodia in 1970 did not widen the war. Since 1965, North Vietnam's forces had occupied the border areas of Cambodia. In March 1970, Hanoi infiltrated into Cambodia over 20,000 Khmer Rouge guerrillas who had been trained in North Vietnam. In April, after Cambodia's government tried to reassert its authority over its own territory — hardly an unreasonable demand — North Vietnam launched an invasion of the country. Hanoi's delegate to the private peace talks in Paris freely admitted to us that North Vietnam intended to bring down the government in Phnom Penh. In May and June, when American and South Vietnamese forces cleared out the Communist sanctuaries, Cambodia was already swept up in the war. If we had not acted, we would have guaranteed the victory of the Communist forces both in Cambodia and South Vietnam. Thus, the charge that our incursion drove the North Vietnamese out of the border areas and toward Phnom Penh is false on its face. The Vietnamese Communists moved deeper into Cambodia two weeks after the fall of Sihanouk and a month before our incursion occurred.
During the war in Vietnam, those who now concoct apologias for Indochina's totalitarians opposed American policies that sought to prevent a Communist victory and the human tragedy that would follow inevitably in its wake. No doubt these apologists are now at least subconsciously motivated by feelings of guilt. Simple ethics holds those who took an action responsible for its consequences. To assign blame for the genocide in Cambodia to those in the United States who sought to prevent a Communist victory, rather than to the Communists who committed the atrocities, is an immoral act in and of itself.
Nixon on the "Secret Bombing"