in Laos – at Vientiane, Pakse, Savannakhet, Long Tieng, and Luang Prabang. These centers supported the ambassador with intelligence, administrative services, and communications as well as the actual air operations under a program called Palace Dog. After the initiation of Operation Rolling Thunder, the sustained aerial campaign against North Vietnam that had begun on 5 March 1965, the Barrel Roll area of operations was divided on 3 April. Barrel Roll was to continue in the northeast while the southern portion of the area, where interdiction missions against the Ho Chi Minh trail were paramount, was redesignated Tiger Hound. Command and control of that area was handed over to the American commander in Saigon, General Westmoreland. At a 29 March 1965 Southeast Asia Coordinating Committee meeting at Udon Thani, Thailand attended by Ambassador Sullivan, representatives from the 2nd Air Division, MACV, and Air America, responsibilities within the Barrel Roll operational area were ironed out. Command and control of the air program would remain in the ambassador's hands. Operational control of U.S. air assets devolved from the commander-in-chief, Pacific Forces (CINCPAC) in Honolulu through his air deputy at Pacific Air Forces or PACAF, to the 2nd Air Division (after 1 April 1966, the Seventh Air Force). Targets could be requested by the Royal Lao government, the CIA or by MACV. Northern Laos, however, was not going to be a priority for the Americans. It was decided at the Honolulu Executive Conference of April 1965 that U.S. aircraft could be used for interdiction in Laos only after close air support needs were met in South Vietnam. General Westmoreland was also granted veto power over bombing, interdiction, and reconnaissance programs outside territorial South Vietnam. That decision placed Barrel Roll behind South Vietnam, Rolling Thunder, and Steel Tiger in order of precedence. Only an estimated two percent of the total U.S. aerial effort in Southeast Asia was going to be utilized in northern Laos. On the offensive (1964–1970) Barrel Roll begins On 12 December 1964, Barrel Roll was approved by Souvanna Phouma. The program originally consisted of only two U.S. bombing sorties per week that were to be conducted by no more than four aircraft in each strike. Due to the nature of the American agreement with the Thai government (most U.S. strike aircraft flew from bases in Thailand), the aircraft had to first fly to South Vietnam, land, and then take off again for