l-O!. The Soviet ICBM d.evel-opment up to now has been charscte"ized by theintroduction " in rapid succession, of nany new missile types hile ;till-retaining most of the older ones. virtually al-1 of the latter are believed. tohave megaton or multi-megaton. yield warheads, rrhile those nore recently deployedrwith an estimated cEP of 3oo-l+00 rn., are reported to have up to eight ivs, eaehwith a yield in the high kiloton range. It woufd thus alpear that the over-a].lsoviet trend in irnproving the capability is si.milar to that in the united states"although the throl'-weight advantage of the ussR over the united states seens tocont inue . 105. The present trends in the evolution of stBM forces a?e not only towards nettmissiles with nore RVs and. higher accuracy - partly as a }esul-t of improvedsubnarine navigation systens - but a-Iso tovard.s modernization of the submarines toacqui.re gres.tex quietness snd expanded operational range. rhe united states isbeginning the deployrnent of the Trid.ent I nissile. With a range of over ?,OOO kn.and a greater throw veight than the poseidon missile, it wj.ll- replace this missilein the 31 Poseidon submarines " Tt will also be deployed in some IO 2l+-tubeTrident submayines when these become operational. The United Kingd.on iscontenpl-ating the acquisition of rrident r nissiles and modern nucl-ea.r-propel-l,edAl 35 /392 I nsltsn Annex j1aqe 4b subnarines for the teplaceldent of its \-subrnarine Po.Iaris fleet. France is buitding a fifth SLSM subnarine, presunably sirnilar to tbe fouT a.l-ready existing. Progra mes for the technical, d.evel-opment of soviet SLBI'{ forces are not well- known; sevelaJ- new missiles have been introduced since the previous united Nations report, holrever. Among these are some 6)+ SS-N nissiles ( soviet tlesignator BSM-50) with 3 I{IRVs of approxinateJ-y 200 kt' yielat" lO5. Manoeuvring re-entry vehicles (t'lanV) lave been discussed since before the SALT I Treaty. The necessary technolo6y is probably availabl-e, al-though no deployment ii tnoun so far. MaRVs vere originally conceived. as an aicl for penetrating an ABM defence, with ABMs abofished by treaty, MaRVs are sti1l bein8 discussed. to improve a.ccuracy against a fiaed target, to attack a tar8et in rootion,
**Analysis**
The text appears to be discussing the development and deployment of intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs) by various countries, including the Soviet Union, United States, United Kingdom, and France. The text highlights the improvements in technology, such as increased accuracy and range, as well as the modernization of submarines. The focus is on the military capabilities of these countries, rather than any economic, social, or environmental aspects.

**Category**
Science and technology, International relations