thetarget. Othermissiles areequipped withon-board computers andguidance systems whiChassumecontrol oncethetargetiswithinthemissile's detection range. Thedevelopment oflong-range supersonic missiles iswelladvanced and firstdeployments havebegun. Thespeedofthesemissiles rulesoutanymidcourse trajectory corrections, andreaction timeforthetargetisdangerously short. Thiswillconsiderably increase thethreat ~onearound awarship: todayavessel needstomonitor everything takingplacewithin aradiusofseveral do~en kilometres, butthatradiuswillprobably havetoincrease inthecomingdecades to several hundred kilometres. /...A/40/535 English Page32 97.Gunshavenotentirely disappeared, however. Missiles aretooexpensive for minororundefended targets. Furthermore, gunsareoftenmoreeffective atshort range.against low-flying targets andinShorebombardment. Gunshavebeen restored toshipsfromwhichtheyhadbeenremoved. and·theyarenowoftenmounted inautomatic turrets without crewsandhavehighratesoffire.Recentexperience hasshownthatclose-range gunscan,insomecases, shootdownincoming missiles as alastlineofdefence. 98.Although atrendtowards thedeployment ofmoremissiles insubmarines isnow emerging, missiles arenotyettheprincipal weapons ofsuchvessels. Themain weaponofthesubmarine continues tobethetorpedo, although itcanalsobe carried insurface ships,aircraft andhelicopters. DuringtheSecondworldWar,a torpedo's useful rangewasperhaps between 2and3kmatbest,whereas wire-guided torpedoes arenowcapable ofhitting targets upto50kmdistant. Torpedoes can alsobeequipped withsearchsystems andhomingdevices thatcandistinguish between therealtargetanddecoys. E.Newtechnologies 99.Research nowunderwaywillprobably againtransform navies. Oneofthemost significant developments isanaerobic propulsion, usingtheprinciple of closed-cycle combustion, whichshouldenablenon-nuclear submarines toremain sUbmerged several weeks(rather thantoday's several days); newhulldesigns that shouldreducethetonnage ofdeep-sea vessels without reducing theirperformance; andunconventional vessels, suchassurface-effect vessels, thatcouldupsetthe balance offorces between surface vessels andsubmarines byvirtueoftheirvery highspeed. Verygreatefforts arebeingmadetoimprove submarine detection and tracking; rapidadvances incomputer technology andcommunications equipment produce constant progress incommand, control, communications andintelligence; and missile guidance andeffectiveness areconstantly beingimproved. 100.Itisstilltooearlytoassesstheimpactofthemostrecent improvements and offutureinnovations. Itisalready clear, however, thattheywillcontinue to strengthen thequalitative sideofthenavalarmSrace.Missiles arebecome increasingly available, whichmakesitpossible fornaviesthathadbeenconsidered coastal uptonowtoacquire fire-power capabilities equivalent inparttosomeof theblue-water navies. Technological developments beginning inthelate1940sand continuing intothe1970s,ledtoaconcentration ofnavalforceinthehandsofa smallnumberofcountries thatweretheonlyonesabletoafford anddevelop complex andexpensive naVies, inparticular nuclear submarines and aircraft-carriers. Now,however, thesituation ismorediverse. Notonlyarethe naviesoftheUnitedStates andtheSovietUnion, andthoseoftheirallies, in competition, butnavalpoweritselfisbecoming morediffuse andthesedevelopments willcertainly haveprofound consequences onthesecurity oftheseas. /...A/40/535 English Page33 F.Existing forces 101.Thefollowing description ofexisting navalforcesisforillustrative pu<poses only.Itiscompiled fromopen,published sources whicharenot necessarily completely reliable noraretheyaccepted byallStatesas authoritative. Thedetails givenareintended asageneral description ofthe sizes,capabilities andnumbers ofvarious navalforces andnavalarmssystems. Theinformation isnotexhaustive andshouldnotbeinterpreted asmaking anyform ofnumerical comparison; indeed, thewidedisparities ofsize,ageandweapon-fit between shipsthatmayappeartobeofthesameclassmaymakecomparisons widely misleading. Tbepurpose ofthedescription intbefollowing paragraphs istoshed somelight,forthereader whomaybeunacquainted withnavalarfairs, onthe extent andcomplexity ofnavalforces. Tothewell-informed itwillbeclearthat
**Analysis**
The text appears to be discussing the development and capabilities of naval forces, including missiles, torpedoes, and submarines. It also touches on the impact of technological advancements on naval warfare and the implications for the security of the seas. The text does not seem to be related to economic development, natural resources, agriculture, industry, transportation, international trade, health, education, employment, humanitarian aid, or culture.

**Category**
Science and technology, Defense