▁together ▁in ▁groups ▁of ▁ 1 0 0 . ▁The ▁theory ▁was ▁that ▁a ▁war head ▁attack ing ▁any ▁one ▁of ▁the ▁sil os ▁would ▁destroy ▁others ▁near ▁it ▁when ▁it ▁expl oded , ▁a ▁concept ▁known ▁as ▁nuclear ▁frat ric ide . ▁One ▁of ▁the ▁arguments ▁in ▁favor ▁of ▁D ense ▁Pack ▁was ▁that ▁it ▁" l ends ▁itself ▁to ▁AB M ▁defense ▁a ▁little ▁better ". ▁ ▁Nevertheless , ▁Re agan ▁went ▁on ▁to ▁state ▁that ▁" we ▁do ▁not ▁wish ▁to ▁emb ark ▁on ▁any ▁course ▁of ▁action ▁that ▁could ▁end anger ▁the ▁current ▁AB M ▁treat y ▁so ▁long ▁as ▁it ▁is ▁observed ▁by ▁the ▁Soviet ▁Union ... ▁we ▁do ▁not ▁wish ▁to ▁build ▁even ▁the ▁minimal ▁AB M ▁system ▁allowed ▁us ▁by ▁the ▁treat y ." ▁In ▁February ▁ 1 9 8 3 , ▁S entry ▁was ▁officially ▁cancel led . ▁ ▁Work ▁on ▁the ▁rad ar ▁system ▁continued ▁and ▁was ▁later ▁renamed ▁the ▁Terminal ▁Im aging ▁Rad ar , ▁with ▁an ▁expanded ▁mission ▁to ▁provide ▁accurate ▁tracks ▁over ▁a ▁wide ▁area . ▁Techn ologies ▁from ▁this ▁program ▁ultimately ▁led ▁to ▁the ▁X - band ▁rad ar . ▁Work ▁on ▁the ▁war head ▁design ▁also ▁continued , ▁but ▁was ▁later ▁moved ▁to ▁a ▁" third ▁generation " ▁design , ▁and ▁in ▁ 1 9 8 3 ▁the ▁Department ▁of ▁Energy ▁noted ▁there ▁were ▁nine ▁such ▁designs ▁under ▁consideration . ▁ ▁Description ▁▁ ▁The ▁bas eline ▁Lo AD S ▁design ▁was ▁a ▁single - stage ▁miss ile ▁consisting ▁of