U.S. Secret Bombing of Cambodia | rabble.ca

The initial operation was authorized by then President Richard Nixon, but without the knowledge or approval of U.S. Congress. The bombings became public knowledge in 1973, after which they were stopped.
The United States dropped upwards of 2.7 million tons of bombs on Cambodia, exceeding the amount it had dropped on Japan during WWII (including Hiroshima and Nagasaki) by almost a million tons. During this time, about 30 per cent of the country's population was internally displaced.