Operation Menu was the codename of a covert United States Strategic Air Command (SAC) bombing campaign conducted in eastern Cambodia from 18 March 1969 until 26 May 1970, during the Vietnam War. The supposed targets of these attacks were sanctuaries and Base Areas of the People's Army of Vietnam (PAVN) and forces of the National Front for the Liberation of South Vietnam (NLF or derogatively, Viet Cong), which utilized them for resupply, training, and resting between campaigns across the border in the Republic of Vietnam (South Vietnam). However, in practice much of the bombing was indiscriminate, and hundreds of thousands of civilians were killed as a result. Estimates of civilian deaths vary from 100,000 to 600,000.
The campaign failed in its objective of preventing North Vietnamese offensives, which continued during Operation Menu. It also enraged the Cambodian public and created a climate that allowed the vicious Khmer Rouge to come to power. Since the Khmer Rouge was responsible for the deaths of an estimated 1.5 million of its own citizens, the indirect impact of Operation Menu can be regarded as even more disastrous than its direct results.
The operation was devised as a method of sending messages to the leadership of the Democratic Republic of Vietnam (North Vietnam) that the newly-installed administration of US president Richard M. Nixon was serious about its continued support for the Saigon government while simultaneously serving as a shield for the withdrawal of US forces from South Vietnam.
The campaign was devised and conducted in secrecy, since an aerial campaign against "neutral" Cambodia would have created a political firestorm in the US (where the war was already deeply unpopular) had it been carried out overtly. In the aftermath of the operation, details surrounding it became known by the United States Congress and the US public, leading to dire consequences for the Nixon administration.
An official United States Air Force record of ...