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,
**Analysis**
The text discusses the development of new and more destructive weapons, the lead time required for the development of new nuclear weapon systems, and the trend towards smaller but more numerous weapons. It also references hearings and reports on military research and development. This suggests that the text is primarily focused on the scientific and technological aspects of military capabilities.

**Category**
Science and technology