 Although airpower was to be a major factor in the defense of Lima Site 85, it could not be applied without limitations and restrictions.The defense of Lima Site 85 was not the sole focus of limited air resources at the time.During this period, the 1968 Tet Offensive was underway in South Vietnam, the Marine outpost at Khe Sanh Combat Base was under siege, and there existed an unprecedented flow of enemy logistical traffic which had to be interdicted.