In 1955, the United States Department of Defence created a special Programs Evaluation Office to replace French support of the Royal Lao Army against the communist organisation Pathet Leo. In 1960, amidst a series of rebellions, fighting broke out between the Royal Lao Army and the Pathet Lao.
Laos was also dragged into the Vietnam War since parts of Laos were invaded and occupied by North Vietnam for use as a supply route for its war against the south. In response, the United States initiated a bombing campaign against the North Vietnamese positions, supported regular and irregular anticommunist forces in Laos and supported South Vietnamese incursions into Laos, which began on this day in 1971.
Massive aerial bombardment against the Pathet Lao and invading NVA communist forces was carried out by the United States to prevent the collapse of Laos’ central government, the Royal Kingdom of Laos, and to prevent the use of the Ho Chi Minh trail to attack U.S. forces in South Vietnam and the Republic of Vietnam. As of 2008, Laos is the most heavily bombed country, per capita, in the world. An average of one B-52 bomb-load was dropped on Laos every eight minutes, 24 hours a day, between 1964 and 1973.