The U.S. began Operation Steel Tiger over the Laotian panhandle and the Vietnamese Demilitarized Zone (DMZ) on April 3, 1965, to locate and destroy enemy forces and materiel being moved southward at night into South Vietnam. However, since circumstances made it a highly complex matter in regard to the neutrality of Laos, target approval had to come from Washington. Additionally, the U.S. ambassadors in South Vietnam, Laos, and Thailand were involved in controlling these U.S. air operations
Late in 1965, the communists greatly increased their infiltration along the Ho Chi Minh Trail. It was decided to concentrate airpower upon a small segment of the Trail closest to South Vietnam and used most extensively by the enemy. As a result, Operation Tiger Hound was initiated in December 1965, utilizing aircraft from the Air Force, the United States Navy, and U.S. Marines, the Vietnamese Air Force, and the Royal Laotian Air Force. On December 11, B-52 heavy bombers were called in to this tactical operation, in their first use over Laos.