. ▁The ▁entire ▁system ▁was ▁pack ed ▁into ▁a ▁cyl inder ▁that ▁looked ▁like ▁an ▁M X ▁and ▁would ▁be ▁sh uff led ▁between ▁the ▁sil os . ▁As ▁the ▁Lo AD S ▁could ▁be ▁in ▁any ▁of ▁the ▁sil os ▁at ▁a ▁particular ▁miss ile ▁site , ▁the ▁enemy ▁would ▁have ▁to ▁exp end ▁two ▁war head s ▁on ▁every ▁sil o ▁to ▁ensure ▁a ▁hit , ▁as ▁one ▁would ▁be ▁assumed ▁lost ▁to ▁Lo AD S . ▁This ▁would ▁not ▁stop ▁a ▁successful ▁counter force ▁attack , ▁but ▁it ▁would ▁make ▁it ▁significantly ▁more ▁expensive ▁in ▁terms ▁of ▁the ▁number ▁of ▁war head s ▁used , ▁potentially ▁requiring ▁more ▁war head s ▁than ▁the ▁S ovi ets ▁had . ▁ ▁With ▁President ▁Jimmy ▁Carter ' s ▁decision ▁to ▁base ▁the ▁M X ▁in ▁a ▁series ▁of ▁less - hard ened ▁horizontal ▁sil os ▁in ▁ 1 9 7 7 , ▁Lo AD S ▁development ▁was ▁acceler ated . ▁The ▁system ▁as ▁a ▁whole ▁was ▁renamed ▁S entry , ▁with ▁the ▁miss ile ▁becoming ▁the ▁Bas eline ▁Terminal ▁Def ense ▁System , ▁or ▁B T DS . ▁Work ▁on ▁M X ▁and ▁S entry ▁was ▁further ▁acceler ated ▁by ▁incoming ▁President ▁Ron ald ▁Re agan ▁in ▁ 1 9 8 1 . ▁However , ▁after ▁another ▁review ▁of ▁the ▁M X ▁program , ▁Re agan ▁chose ▁a ▁different ▁M X ▁deployment ▁concept ▁and ▁cancel led ▁S entry , ▁stating ▁that ▁it ▁would ▁viol ate ▁the ▁AB M ▁treat y . ▁As ▁the