▁organiz ational ▁structure ▁of ▁the ▁U . S . ▁Air ▁Force . ▁ ▁On ▁ 1 ▁September ▁ 1 9 9 1 , ▁Tw enti eth ▁Air ▁Force ▁was ▁react iv ated ▁by ▁Str ateg ic ▁Air ▁Command ▁( S AC ) ▁and ▁became ▁responsible ▁for ▁all ▁land - based ▁Inter cont inental ▁Ball istic ▁Miss iles . ▁On ▁ 1 ▁June ▁ 1 9 9 2 , ▁Warren ▁transition ed ▁from ▁the ▁in activ ating ▁S AC ▁to ▁newly ▁established ▁Air ▁Com bat ▁Command , ▁and ▁on ▁ 1 ▁July ▁ 1 9 9 3 ▁to ▁the ▁Air ▁Force ▁Space ▁Command . ▁This ▁real ignment ▁was ▁designed ▁to ▁take ▁advantage ▁of ▁the ▁similar ities ▁between ▁miss ile ▁launch ▁and ▁space ▁launch ▁operations . ▁The ▁ 9 0 th ▁Str ateg ic ▁Miss ile ▁Wing ▁was ▁also ▁renamed ▁the ▁ 9 0 th ▁Miss ile ▁Wing . ▁The ▁wing ▁became ▁the ▁ 9 0 th ▁Space ▁Wing ▁on ▁ 1 ▁October ▁ 1 9 9 7 . ▁ ▁With ▁the ▁rat ification ▁of ▁the ▁Str ateg ic ▁Ar ms ▁Red u ction ▁Tre aty ▁I , ▁the ▁U . S . ▁had ▁until ▁December ▁ 2 0 0 1 ▁to ▁reduce ▁its ▁nuclear ▁ar sen al . ▁As ▁a ▁result , ▁the ▁ 9 0 th ▁Miss ile ▁Wing ▁reduced ▁the ▁fleet ▁from ▁three ▁' re entry ▁vehicles ' ▁perm iss ible ▁to ▁a ▁single ▁re entry ▁vehicle ▁configuration . ▁On ▁ 6 ▁August ▁ 2 0 0 1 , ▁all ▁ 1