due to the continuous withdrawal of american forces as part of the ongoing policy of vietnamization, at the time of the invasion fewer than 10,000 u.s. combat troops remained in south vietnam, and most of them were scheduled to leave within the next six months. the number of combat aircraft stationed in southeast asia was less than half that of its peak strength in 1968–1969. at the beginning of 1972, the u.s. air force had only three squadrons of f-4s and a single squadron of a-37s, a total of 76 aircraft, stationed in south vietnam. another 114 fighter-bombers were located at bases in thailand. 83 b-52 bombers were stationed at u-tapao rtafb, thailand and at andersen air force base, guam. the u.s. navy's task force 77 (stationed in the gulf of tonkin), had four aircraft carriers assigned to it, but only two were available at any one time to conduct operations. their air wings totaled approximately 140 aircraft.