Operation Menu: the secret U.S. bombing of Cambodia

The bombing campaign in Cambodia wasn't supposed to be something the American public knew much about. Between 1969 and 1973, the United States carried out Operation Menu, a covert campaign that extended the Vietnam War into neighboring Cambodia, even though Cambodia was officially a neutral country.

The scale was enormous. The source account puts the amount of bombs dropped at roughly half a million tons and attributes at least 100,000 civilian deaths to the campaign. What makes the operation even more striking is how deliberately its existence was concealed. Henry Kissinger reportedly insisted that simply classifying Menu as "top secret" wasn't enough and demanded "absolute and total secrecy."

Congress was reportedly kept in the dark because the administration believed lawmakers would never authorize such a campaign against a country the United States was not officially at war with. Nixon had also been elected promising to end the war in Vietnam, making the secret expansion into Cambodia politically explosive if it became public. The operation therefore wasn't only about the bombing itself, but about how an enormous military campaign could be carried out while deliberately keeping Congress from knowing its full extent.