talies the lead over policy" creating weapons for vrhich needs have to be invented. r"nd deployment theories have to be readJusted" It :is also a fact that a verysubstantial lo"tion of the r,rorkl r s total scientific and technicaf nanpower is elgaged in military research and. development, involving the lmprovement of existing ".realons and developing new weapon systems, It is obvious that a situationinvolving an effort of this nagnitude must lead to the production of new and more destructive rreapons. One shou-l-d also keep in mind that the long lead--tine required.for the developrrrent of nev nucJ-ear-weapon systems does bring in significant qr.'-al.ilative chanJes Lo the action/reaction proce;s since one sidc, vishinu Lo catch up r{iti the oLher side, has necessarily to take inLo accounl possibfe futrfe cierrelopments by the other side over significantl-y long tirne frames. 63. fn the 1950s and carly l95os, the nueLear arns race vas charaeterized by the cleveJ-opment of eve? more pornlerful weapons. The first fusion device detonated bythe United S-tates in )-952 lnad a yield reported to be about 10 l!it. '-tvo years le.terthe United. States tested a 'weapon with a 15 I'lt " yie1d, a-nd. in 1961- the USSR exploded a fusion weapon with an estimated yield of about 50 tUt. In later years, the trend has been tolrards small-er but more numerous rreapons. 0n 8,n individ.ualnissile, for instance, a single large rnrarhead may be rcptaced by several snaller ones of the sane total weight: in many cases this leads to a decrease in the total noninal yield- although the nrmber of varheads increases. Thus the 20 NIt. varhead ral Ah^h' +ha .^,1116- .r'.,- ,,-^- .'- +r' ^ --^-.- . rh.iF ^hrhl 6F SOUe Of the mosl comprehensive and authoritative are the folloving: (a) I{earings before a Subcomittee of the Connrittee on Appropriations,