The Seventh Air Force (PACAF) wanted additional B-52s missions flown in the war zone. B-52 missions from Andersen and Kadena, however, required long mission times and aerial refuelling en route. Having the aircraft based in South Vietnam made them vulnerable to attack. It was decided that, as the base at U-Tapao was being established as a KC-135 tanker base, to move them all out of Don Muang and to also base B-52s at U-Tapao where they could fly without refuelling over both North and South Vietnam.