[citation needed] Bombing of the trail system had begun on 14 December 1964 with the advent of Operation Barrel Roll.

Due to increasing U.S. intelligence of the build-up of regimental-size PAVN units operating in South Vietnam, the increased American military presence in that country, and the initiation of Operation Rolling Thunder, American planners in Washington and Saigon decided that the bombing in southeastern Laos should be stepped up.

[1] It was estimated by U.S. intelligence analysts that, during 1965, 4,500 PAVN troops were infiltrated through Laos along with 300 tons of materiel each month.

[2]: 55  By the end of 1967 and the absorption of Steel Tiger operations into Commando Hunt, 103,148 tactical air sorties had been flown in Laos.

[4]: 197 This article incorporates public domain material from the Air Force Historical Research Agency