In Laos, Operation Barrel Roll, the name given to the first phase of the bombing plan approved by President Lyndon B. Johnson on December 1, begins with U.S. planes attacking "targets of opportunity" in northern Laos.
This operation was initiated in response to a Pathet Lao offensive in the Plaine des Jarres in north central Laos. The Pathet Lao were communist guerrillas who were fighting to overthrow the Royal Lao government. Operation Barrel Roll was designed to provide air support for the Royal Laotian Army and CIA-trained Hmong (mountain people) irregular forces led by Gen. Vang Pao. In addition to these operations, there was also another part of the war in Laos which was conducted in the eastern part of the country along the Ho Chi Minh Trail, which ran out of North Vietnam through Laos and south along the South Vietnamese-Cambodian border. The North Vietnamese used this trail network as the main avenue by which they supplied and reinforced their troops in South Vietnam. Operations Steel Tiger and Tiger Hound were initiated in April and December 1965 respectively to bomb the trail in an intensive and protracted attempt to interdict the massive amounts of men and supplies moving along the corridor. By 1973, when Operations Barrel Roll, Steel Tiger, and Tiger Hound were terminated, Laos had become the most heavily bombed country in the world. During these operations, allied aircraft dropped more than 3 million tons of bombs, three times the amount dropped on North Vietnam. U.S. spending for these bombing campaigns was 10 times that of the Laotian national budget.