▁always ▁win . ▁ ▁In ▁practice , ▁the ▁price ▁of ▁the ▁inter ceptor ▁miss ile ▁was ▁considerable , ▁due ▁to ▁its ▁s oph istic ation . ▁The ▁system ▁had ▁to ▁be ▁gu ided ▁all ▁the ▁way ▁to ▁an ▁inter ception , ▁which ▁demanded ▁guidance ▁and ▁control ▁systems ▁that ▁worked ▁within ▁and ▁outside ▁the ▁atmosphere . ▁The ▁N ike ▁Ze us ▁was ▁expected ▁to ▁cost ▁about ▁$ 1 ▁million , ▁about ▁the ▁same ▁as ▁an ▁IC B M . ▁However , ▁due ▁to ▁their ▁relatively ▁short ▁ranges , ▁an ▁AB M ▁miss ile ▁would ▁be ▁needed ▁to ▁counter ▁an ▁IC B M ▁wherever ▁it ▁might ▁be ▁aim ed . ▁That ▁implies ▁that ▁do z ens ▁of ▁intercept ors ▁are ▁needed ▁for ▁every ▁IC B M . ▁This ▁led ▁to ▁inten se ▁deb ates ▁about ▁the ▁" cost - exchange ▁ratio " ▁between ▁intercept ors ▁and ▁war head s . ▁ ▁Cond itions ▁changed ▁dram atically ▁in ▁ 1 9 7 0 ▁with ▁the ▁introduction ▁of ▁multiple ▁independently ▁target able ▁re entry ▁vehicle ▁( M IR V ) ▁war head s . ▁Sud den ly , ▁each ▁launch er ▁was ▁throwing ▁not ▁one ▁war head , ▁but ▁several . ▁These ▁would ▁spread ▁out ▁in ▁space , ▁ens uring ▁that ▁a ▁single ▁inter ceptor ▁would ▁be ▁needed ▁for ▁each ▁war head . ▁This ▁simply ▁added ▁to ▁the ▁need ▁to ▁have ▁several ▁intercept ors ▁for ▁each ▁war head ▁in ▁order ▁to ▁provide ▁ge ographical ▁coverage . ▁Now ▁it ▁was ▁clear ▁that ▁an ▁AB M ▁system ▁would ▁always