The Decisive Factors in the UN Forces’ Defense of the Pusan Perimeter in 1950 Korean War

7/30/2019 The Decisive Factors in the UN Forces Defense of the Pusan Perimeter in 1950 Korean War

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TheDecisiveFactorsintheUNForcesDefense

ofthePusanPerimeterinthe1950KoreanWar

GOV-451

KyleGaines

11/19/12

1

1Battle of Pusan Perimeter, Wikipedia Series on the Korean War, (Wikipedia, 4 September2012).


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1.Introduction

HistoricalContextandOverviewoftheKoreanWar

TheKoreanWarisalsoknownastheforgottenwarbecauseoftherelative

dearthofscholarshipandwritingonthesubject.2Despitethisscarcityhowever,the

KoreanWarwasatremendouslysignificantconflictwithAsiansecurityimplications

lastinguntilthepresentday.TheKoreanWarwasthefirstproxywarthatwasa

partoftheoverarchingstrugglebetweentheUnitedStatesandtheUSSR.Although

theUSSRcontributedadvisersandmilitaryresourcestotheconflict,noSoviet

soldiersphysicallyengagedincombatoperations.Conversely,Americansoldiers

formedacriticalcomponentoftheUNcoalitionthatreactedinresponsetoNorthKoreanaggression.

Thisconflictbeganon25June1950,whenNorthKoreanPeoplesArmy

(NKPA)forcescrossedthe38thparallelwiththesupportofamassiveartillery

barrageandRussianadviserswithoutwarning.3Afterthisaction,theU.N.

respondedwithacalltoarms,andacoalitionofnationsincludingtheRepublicof

Korea(ROK),TheUnitedStates,Britain,AustraliaandJapancommittedtroopsand

resourcestothedefenseofSouthKorea.4TheUNcommitmentoftroopsand

AmericaneffortstostemtheNorthKoreanadvanceledtothecreationofthe

defensiveperimetercalledPusanbyAugust1stunderUSEighthArmyGeneral

WaltonWalker5(SeeFigure2).Thewarhadchangedcharacter,andnolongerwas

theprimarilyAmericanandSouthKoreanforcerelyingonineffectiveweaponsand

alackofarmortostemthetideofarelativelywell-organizedandequippedenemy.6

Miraculously,theunderequippedandillpreparedUNforcewasabletoholdthe

2

Harry G Summers, Jr., Korean War Almanac, (New York, NY: Facts on File Inc., 1990). Xiii3

Ibid. xiii4

Ibid. xiv5

Edwin P. Hoyt, The Pusan Perimeter, Korea, 1950, (Briarcliff Manor, NY: Stein and DayPublishers, 1984). 1396Ibid. 139


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NKPAatthePusanPerimeter,whichboughttimeforGen.DouglasMacArthurs

famousInchoninvasionon15September1950. 7

8

AftertheinvasionatInchon,UNforcesnotonlysuccessfullydroveNKPA

forcesbacktothe38thparallel,butalsocontinuedtheiradvanceupthepeninsulato

theYaluRiver.9Atthisstageinthewar,ChineseCommunistForces(CCF)entered

thefrayandbetweenDecember1950andJune1951,launchedanoffensivethat

droveUNforcesbackdowntothe38thparallel.10FromJuly1951untilthe

armisticeinJuly1953,thewarresembledthestatictrenchwarfarethatcomprised

7

Summers, Korean War Almanac, xiv8J. McCracken, A Brief Timeline of the Korean War (15 November 2012).

9

Ibid.10

Ibid.

Figure8


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WorldWarI,andresultedinaceasefirebetweentheNorthandtheSouththathas

lasteduntilthepresentday.11

NorthKoreanGoals

ThegoalsoftheNKPAwereprettyclearlyevidentfromthestartofthewar.

Inamanifestopublishedon8June1950,newspapersinPyongyangprinteda

pamphletreleasedbytheCentralCommitteeoftheUnitedDemocraticFrontof

NorthKoreaoutliningitsaimsforthenextfewmonths.12Themanifestosought

electionstobeheldinthenorthandthesouthandthenewparliamenttositno

laterthan15August.13OfcoursetherewasnomentionoftheRepublicofSouth

Korea,sobyimplicationitseemsasthoughNorthKoreawasannouncingits

intentiontoinvadetheSouthasearlyas8June1950.14Politically,theNorth

KoreanssoughttocollapsethegovernmentofDr.SyngmanRheeandmilitarilythey

soughttocausethedisintegrationoftheROKsarmy.15Inbothoftheseendeavors

theNorthKoreansfailed,andthesuccessfuldefenseatPusanwasamajorreason

why.Thispaperwillinvestigatethefactorscontributingtothatdefense.

UNCoalitionGoals

OneofthefascinatingaspectsoftheKoreanWaristhatthegoalsofthe

UnitedStateschangedmultipletimesduringthecourseoftheconflicteventhough

theUNhadapprovedonlyonesetofobjectives.DespitethedecisionbyMacArthur

todrivepastthe38thparallelinpursuitoftheNKPAaftertheinvasionofInchon,

thispaperislimitedtoadiscussionoftheUNgoalsupuntiltheNKPAwasdriven

backtothe38thparallel.TheinitialgoaloftheUNcoalitionwasarticulatedinaU.N.

11

Ibid.12Fehrenbach, This Kind of War, 313Ibid. 314Ibid. 315Millett,TheKoreanWar,18-19


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resolutionthatwaspassedinarecord4hours.16Passingthisresolutionwasonly

possibleduetoamajortacticalerrorbytheUSSR,whichwastheirdecisionto

boycotttheU.N.forafewmonths.17TheywereprotestingTaiwansretentionof

theirSecurityCouncilseatinthewakeoftheCommunisttakeoverofMainland

China,andasaresulttheyforfeitedtheirvoteandcouldnotvetotheresolution.18

TheUNresolutionhadthreeparts:1)theimmediateendoffighting;2)the

withdrawalofNorthKoreabehindthe38thparallel;and3)andallmembersassist

theU.N.andrefrainfromassistingNorthKorea.19Althoughnotallmembers

assistedandtheendtothefightingwasnotimmediate,theUNcoalitiondidachieve

itsprinciplegoalofdrivingNorthKoreabackbehindthe38thparallelshortlyafter

Inchon.

Argument

ThispaperseekstoinvestigatethereasonswhytheUNcoalitionwasableto

defendthePusanPerimetersuccessfully.TheconventionalwisdomoftheKorean

ConflictsuggeststhatU.S.airpowerinterferedwithNorthKoreanlogisticstosuch

anextentthattheabilityoftheNKPAtobreachandexploittheperimeterwas

dramaticallyundercut.Thispaperhowever,willpartiallychallengethe

conventionalwisdombyexaminingfivepotentialfactorsthatledtothesuccessful

defenseoftheperimeter.1)NKPAlogisticalineffectivenessasaresultofits

inherentincompetenceandU.S.airattacksonsupplylines,2)NorthKoreantactical

andstrategicineptitude,3)U.S.naval,airandtechnologicalsuperiorityandthe

successfulapplicationoftheseadvantagesinsupportingthedefenseofthefront,4)

thesimplefactthattheUNcoalitionhadasmaller,moreconcentratedareato

defendwithinteriorlinesofcommunicationandsuperiorlogisticsandfinally5)

thatthefrictionofwar,asClausewitzscalledit,woreontheNKPAsextendedlines

16T.R. Fehrenbach, The Fight for Korea, (New York, NY: Grosset and Dunlap, 1969). 61-6217

Ibid. 6218Ibid. 6219

Ibid. 62


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andcausedadeteriorationintroopstrengthandequipmentrelativetoincreasing

UNtrooplevels.

Throughanexaminationofthese5factors,thispaperwillarriveatthe

conclusionthatasynthesisofUStechnologicalair,navalandtechnological

superiorityalongthefront,thesmallerandmoreconcentratedlineandeffective

logistics,andthefrictionofwarwerethemostcompellingfactorsthatexplainthe

haltoftheNKPAsadvanceatPusan.

Scope

Thescopeofthispaperisnecessarilylimitedtotheestablishment,defense

andholdingofthePusanPerimeterbyUNcoalitionforces.Althoughtheattackat

Inchonon15Septemberwasamajorturningpointintheconflict,thispaperwill

showthatbySeptember15th,NKPAeffortstobreachthePusanPerimeterhad

stalledandgroundtoahalt.Thus,examiningthesuccessfulPusanPerimeter

defenseisworthyofanalysisonitsownmeritsseparatefromInchon.Reaching

beyondtheselimitswouldleadtoanunsatisfactoryandinsufficienttreatmentofthe

featuresofthedefenseoftheperimeter.

Alsoofnote,theBattleofPusanPerimeterwasactuallyaseriesof

simultaneousassaultsbyNKPAforcesinanattempttobreakthroughtheperimeter

andconquerthewholepeninsula.20Asaresult,thechronologyofthebattlegets

somewhatconvoluted.ThispaperwillpresentaroughtimelineoftheBattleof

PusanandhowitfitintothebroaderKoreanWar.Moreimportantthanthedetails

oftheindividualskirmishesalongthelinearetheoverallfactorsandprevailing

conditionsthatledtothesuccessfuldefenseoftheperimeter.Thispaperwill

investigatethesetrendsratherthanprovideanecdotaldescriptionsofclashesalong

thefront.Notonlywouldsuchdescriptionsobfuscatethecoreargumentofthe

20Roy E. Appleman, South to the Naktong, North to the Yalu, (Washington, DC: Center ofMilitary History, US Army, 1992). P. 289


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paper,butalsothefrequenciesanddistinctionsbetweensuchclashesareextremely

complexanddifficulttodifferentiate.

Structure

Thispaperisbrokeninto3sections.First,itwillexaminethehistorical

contextandoverviewofthedefenseoftheperimeter,startingwiththeNKPA

invasionofthe38thparallelandendingwiththeinvasionofInchon.Second,itwill

analyzethefivepotentialargumentsforwhythedefenseofthePerimeterwas

successfulbyexaminingtheirevidenceandthechallengestoeachargumentand

thensynthesizingtheargumentpreviouslyoutlined.Finally,thispaperwilldiscuss

theconsequencesofthesuccessfuldefenseofPusanfortheKoreanWarandthe

ColdWarmorebroadly.

2.HistoricalContextandTimelineoftheBattleofPusanPerimeter

DelayingAction

TheKoreanWarbeganon25 JulywiththeNKPAspredawnstormingofthe

38thparallelbehindathunderousSoviet-Styleartillerybarrage.21Figures1and2

showtheprogressionoftheinvasionfromdifferentangles,andwhatismost

strikingistherapiditywithwhichtheattackoccurred.

22

21

Allen R. Millett, The Korean War, (Dulles, Virginia: Potomac Books, Inc., 2007). 1822Ebb and Flow, BBC News.http://news.bbc.co.uk/2/shared/spl/hi/pop_ups/03/uk_korean_war/html/3.stm

Figure1


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Figure1showshowdrasticallythefrontlinechangedfromthewarsstartto

itsconclusion.ThemassiveinequalitybetweentheROKandtheNKPAinboth

quantityandqualityofforcesbecameevidentveryearlyintheconflict.NKPAforces

were17milesnorthofSeoulby25-26JunewhentheU.S.governmentfirstbeganto

actontheinvasion.24U.S.troopswereengagedincombatactionsby5Julyand

betweenJuly5and1August,ROKandAmericansoldierswereengagedina

delayingactioninordertorushasmanymenandequipmentintotheremaining

ROKheldterritoryaspossible.25Asof1August,thePusanPerimeterwas

established,andROKandAmericanforceswerenolongertryingtostemthetideof

23Donald Pittenger, An Anniversary, (25 June 2008).24

Hoyt, Pusan Perimeter, 2425

Ibid. 40-139

Figure2


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theNKPAadvancewithinferiorweaponsandorganization. 26Figure2showsthe

contoursoftheperimeterduringthedefenseoftheperimeterbeginningon1

August1950.

TheBattleofthePusanPerimeter

BetweenAugust1standSeptember1st,TheNPKAforceslaunchedaseriesof

attacksthatwererepeatedlybeatenbackbyUNforces.KoreanWarscholarRoy

ApplemaneffectivelyexplainsthenatureoftheBattleofPusanPerimeter:

TheNorthKoreans,inpreparingtoattackthePusanPerimeterandits

communicationsystem,hadavailablefourlinesofadvancetowardPusan:(1)through

orpastMasansouthoftheconfluenceoftheNamandNaktongRivers,(2)throughthe

NaktongBulgetotherailandroadlinesatMiryang,(3)throughTaegu,and(4)

throughKyongjuanddowntheeastcoastcorridor.Theytriedthemallsimultaneously

inAugust,apparentlybelievingthatiftheydidnotsucceedatoneplacetheywouldat

another.27

Althoughalloftheseengagementshaveuniquefeatures,thecentralunifying

tenetofeachencounterwasthatUNforcessuccessfullyheldtheline.Althoughin

somecasesNKPAforceswereabletobreakthroughtheperimeter,theywerenever

abletoexploitthisadvantageandwerealwayseventuallydrivenback. 28

AsAugustworeon,NKPAadvanceswerecontinuallyunsuccessful.29AsT.R

Fehrenbachwrites,asAugustwaned,theNorthKoreansbegantorealizethatthe

onlywaytheycouldnowhopetogainadecisionwasbyafrontalattackagainstthe

perimeter30FehrenbachdescribestheGreatNaktongOffensiveastheheavest

26

Ibid. 13927Appleman, North to the Yalu, p. 289.28

Appleman, South to the Naktong, P. 46629T.R. Fehrenbach, This Kind of War, The Classic Korean War History, (Washington DC:Brasseys inc., 1963). 13830Fehrenbach,ThisKindofWar,138


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fightingoftheKoreanWarwhereeveryAmericanDivisionimmediatelycame

underheavypressure.31

IntheearlydaysofSeptemberthefightingwasfierceandindecisive,butby

15SeptembertheUNforceshadheldtheirgroundandthefightingalongthe

Perimeterbecamequiet.32TheGreatNaktongOffensivehadfailedtobreakthrough

andtakeTaeguorPusan,andUNforceswerenowinthepositiontotakethe

offensive.33On15Septemberthatisexactlywhathappened,andtheresulting

invasionofInchonandasubsequentbreakoutfrompositionsinPusanon18

SeptemberendedthefightingaroundPusanfortherestofthewar.34

3.AnalysisoftheFactorsLeadingtotheSuccessfulDefenseofthe

PerimeterandtheNKPAFailuretoPenetrate

Thepossibleexplanationsforthedefenseoftheperimetercanbedivided

into5broadfactorsincluding1)NKPAlogisticalineffectivenessbothdueto

inherentproblemsandU.S.airattacks,2)NKPAtacticalandstrategicmistakes,3)

U.S.firepowersuperiorityalongtheline,4)thesmaller,easiertodefendperimeter

withsuperiorUNlogisticsand5)thefrictionofwarargument.

1)NKPALogisticalIneffectiveness

TheconventionalwisdomoftheKoreanWaremphasizespoor,disorganized

andineffectiveNorthKoreanlogisticscausedbyinnateproblemswithintheNKPA

andanaggressiveAmericanbombingcampaignaimedatdisruptingNKPAsupply

lines.ThelogicofthisargumentisthatUNforcesinterferedwithNKPAlogisticsto

suchanextentthatitsabilitytosupplythefrontlinewasgreatlyhindered.James

31Fehrenbach,ThisKindofWar,14132

Fehrenbach, This Kind of War, 148-15933

Hoyt, Pusan Perimeter, 27334

William T. Bowers, William M. Hammong, George L. MacGarrigle, Black Soldier, White Army:The 24th Infantry Regiment in Korea, (Honolulu, Hawaii: University Press of the Pacific 2005). p.175


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StokesburyarguesthattheAmericanbombingcampaigndestroyedlogistics,

transportandinfrastructureandforcedtheNKPAresupplytohideduringtheday

andtravelbynight.35AccordingtoStokesbury,theseactionspreventedtheNKPA

frombeingsuppliedinthesouth.36Indeed,ThesupremacyoftheFifthAirForcein

theskiesoverKoreaforcedtheNorthKoreansinthefirstmonthofthewartoresort

tonightmovementofsuppliestothebattlearea.37Whileitistruethatsupplyand

communicationsproblemsinhibitedtheNorthKoreansfromexploiting

breakthroughstotheirfullpotential,thisfactorastheprincipalreasonforthe

failuretopenetratethePerimeterisflawedforatworeasons.

Firstofall,eveninspiteofthepressureputonsupplylines,itisactually

quiteremarkablehowwellNKPAforceswerestillabletosupplythefront.38

Applemanwrites:

TheUnitedNationsaireffortfailedtohaltmilitaryrailtransport.Ammunition

andmotorfuel,whichtookprecedenceoverallothertypesofsupply,continuedto

arriveatthefront,thoughindiminishedquantity.Therewasstillaconsiderable

resupplyofheavyweapons,suchastanks,artillery,andmortars,atthefrontinearly

September...39

Secondly,T.R.Fehrenbacharguesthatairpoweralonewascertainlynot

decisiveintheKoreanconflictbecauseofthefragmentationofthecountry,andthe

abilityoftheNKPAtotransportsuppliestothefrontbywhatevermeanspossible,

includingfoottransport.40Heassertsthatagooddealofsuppliesstillarrivedatthe

frontandWesternperspectivesofmassesofmilitarymaterielsimplydidnotexistin

NorthKoreainthefirstplace.41Figure3showstheinitialNorthKoreanaxisof

35James L .Stokesbury,A Short History of the Korean War, (New York, NY: Harper Perennial1990.) 47-48, 66.36Ibid.47-48,6637Appleman, North to the Yalu, p. 37738

Ibid. 39439Ibid. 39440Fehrenbach, This Kind of War, 11441Ibid. 114


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advanceandtherelativelyconnectedalbeitdamagednetworkofroadsthatstill

allowedfortransportofsuppliestothefront.Consideringthesechallengestothe

conventionalwisdom,theremustbeotherexplanationsforthefailureoftheNKPA

andthesuccessoftheUN.

42

42Hoyt, Pusan Perimeter, 99


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2)NKPAMilitaryIncompetence

Onepotentialreasonforamilitaryfailurethatmustalwaysbeconsideredin

warfareismilitaryincompetence,whethertacticallyorstrategically,onthepartof

thelosingside.Althoughpoordecision-makingisoftentheculpritinmilitary

failures,thisargumentdoesnotholdmuchwaterinthecaseoftheassaultonthe

PusanPerimeterbytheNKPA.

Theonlyrealdefenseofthisargumentisthesuggestionthatattackingat

multiplepointsalongtheperimetercausedadiffusionofmilitaryresourcesand

ineffectivelyemployedtheprincipleofmasstobreakthroughtheUNline.North

Koreancommanderswereapparentlyoperatingundertheassumptionthatifthey

didnotsucceedinoneplacethattheywouldinanother.43Itisacompelling

argumentthatgiventhenatureofthelimitationsonNorthKoreanresources,the

NKPAshouldhavepursuedamoreconcentratedmaineffort,butthisisasignificant

tacticalquestionthatwouldrequiremuchmilitaryknow-howtodebateinthefirst

place.ItispossiblethattheoverextendedNorthKoreansupplylinesandattrition

preventedthesuccessfulconcentrationandexploitationofbreakthroughsintheline,

butthisreasonismoreconnectedtofactor#5,thefrictionofwar,ratherthan

militaryincompetence.

Contrarytothisargument,NorthKoreanmilitarycommandersseemtohave

beenhighlyadepttacticiansintheearlystagesofthewar.Theirrapidpushto

PusaninthefirstplaceandthefactthattheytacticallyoutmaneuveredUNforceson

anumberofoccasionsandbrokethroughthePerimeteratvariouspointsinthe

month-and-a-halflongbattlesuggeststhatfactorsotherthanmilitaryincompetence

wereattherootofthefailuretopenetratethePerimeter.NorthKorean

commanderssuccessfullyflankedandinfiltratedtroopstotheenemysrearallthe

waydowntheKoreanPeninsulatoPusan.44OncethePerimeterwasestablished,

NKPAcommandersalsorealizedthatwithasmaller,harder-to-flankfront,that

43Appleman, North to the Yalu, p. 28944Fehrenbach, This Kind of War, 138


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othertacticswouldhavetobeadopted,namelythefrontalassaultthatthey

pursued.45ItseemshardtocontendthatNKPAcommanderswereincompetentin

lightofthesewellthought-outdecisionsandrealizationscombinedwiththeirinitial

successes.

3)USAir,Naval,andTechnologicalQuality

ThethirdpotentialfactorthatexplainstheUNdefenseofthePusan

Perimeterissuperiorairandnavalfirepower,andmoreadvancedtechnologyto

supportthefront.Thisfactorwillbecalledthefirepowerargumentforthe

purposesofthispaper.RatherthanfocusingonUNattacksonsupplylines,whichthispaperalreadychallengedasalegitimatefactor,thisargumentfocusesmoreon

theuniquesuperiorityofUNfirepoweralongthefront.

ThelogicofthefirepowerargumentisthatUNfirepowersuperioritywas

partiallyaresultofamoreeclecticcoalitioncontributingsuppliesandtroopstothe

conflictandpartiallyasaresultoftheextremematerialadvantagesconferredtothe

UNbytheU.S.warmachine.

Thefirepowerargumenthassignificantevidencetosupportitsclaims.T.R

Fehrenbacharticulatesthisargumentwhenhewrites,Withoutcompletecontrolof

theairandseasduringthedarkdaysofmid-summer1950,theUNpresenceonthe

KoreanPeninsulawouldhaveended. 46AccordingtoFehrenbach,UNair

superioritywaslessimportantforattackingNKPAsupplylines,butabsolutely

essentialforsupportalongthefront.47TherelativelackofartilleryinKoreaduring

theBattleofPusanPerimeterelevatedtheimportanceofairpowerbecauseitwas

usedtosupportthefrontlinestogreateffect.48Fehrenbachgoessofarastosay

thatWithoutconstantaircoverovertheperimeter,withoutstrafingthatgreatly

45Ibid. 13846

Ibid. 11447

Ibid 11448

Ibid. 114


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hamperedNKPAattacksitisprobablethatthePerimeterwouldhavebeen

breachedfatally.49ForFehrenbachandotherscholars,airpowerwasessentialto

thewareffort.

Anotheraspectofthefirepowerargumentmorelooselyconstruedisthe

uniquetechnologicaladvantagesoftheUNrelativetotheNKPA.SignalsIntelligence

(SIGINT)specificallywasamajoradvantageheldbytheUNinthedefenseofthe

perimeter.50UNforcesusedasubsetofSIGINT,CommunicationsIntelligence

(COMINT)tolocateairfieldsandaircraftforbombing,locatecentersofartillery

distributionandgiveGeneralWaltonWalkerinformationonNKPAtroop

movements.51Thisadvantageprovidedanewanduniqueformoftechnological

supportthatcertainlyimprovedtheUNdefenseeffortandalthoughnotkinetic

firepower,itcanstillbeconsideredanimportantforceinthedefenseofPusan.

UNforcesalsohadsuperiorfirepowercapabilitiesonthegroundaccording

toAppleman.Hediscussestheseadvantageswhenhewrites,{NorthKorean

Forces}werenotcapableofexploitingabreakthroughinthefaceofmassiveair,

armor,andartillery...52

Theonlyrealchallengetothisargumentisthatalloftheseadvantages

considered,NorthKoreanforceswerestillveryclosetooverrunningthePusan

Perimeter,especiallyintheGreatNaktongOffensive.53Eveninspiteofthesupport

providedbyfirepowersuperiority,therestillmustbeotherfactorsthatatleast

partiallycontributedtothesuccessfuldefenseoftheperimeter.

ItisclearfromtheevidencethatU.S.air,navalandgroundfirepower

superioritycombinedwithtechnologicaladvantageshadasignificantimpactonthe

BattleofPusanPerimeter.TheeffectofUNfirepowercannotbeunderstatedand

49

Ibid. 11450David A. Hatch and Robert Louis Benson, The Korean War: The SIGINT Backround, (FortMeade, MD: NSA 2000) Accessed Electronically. The Pusan Perimeter51Ibid.PusanPerimeter52Appleman, North to the Yalu, p. 46653Fehrenbach, This Kind of War, 141-142


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wascertainlyanecessaryalbeitprobablynotsufficientfactorintheUNdefenseof

thePerimeter.

4)SmallerLine,SuperiorLogistics,ForcestoSpace

OneofthemoreintriguingexplanationsforwhytheUNheldthelineat

PusanisasimplearithmeticargumentandwasfirstpresentedbyB.H.LiddellHart.

Knownastheratioofforcestospace,thisargumentwaspublishedinhis1960

bookDeterrentorDefense.54Theratioofforcetospaceobservesthatforatleasta

centuryandahalf,ithastakenrelativelylesssoldierstoholdafrontofequal

distance.55Hartobservesthatthedefensehasbeengainingagrowingamaterial

ascendancyovertheoffense56Implicitinthistheoryisthatnotonlywasdefense

growingrelativetooffenseduringthistimeinhistory,buttheconcentrationin

densityreducedmaneuverabilityandmoreeasilyallowedfortheholdingofthe

frontbyUNforces.Simultaneously,thepoorroadsandmountainousterrainalong

thePusanPerimeteronlyexaggeratedthesuperiorityofthedefenseandallowedan

initiallysmallerforcetoestablishadefensiveperimeter.Figure4showsthe

mountainousconditionsandbrokenterrainthatfavoredthedefendersofthe

perimeter.

54 B.H. Liddell Hart, Deterrent or Defense, (New York, NY: Frederick A. Praeger, Inc. 1960).55Hart, Deterrent, 9756Ibid. 97


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57

Ifwedeveloptheratioofforcetospacetheorytoitsmorespecificcontextat

Pusan,itgainsevenmoreweight.Accordingtothelogicofwhatthispaperwillcall

thearithmeticargumentwhichincorporatestheratioofforcestospacebutalso

57Hoyt, Pusan Perimeter, 122


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examinesotherfactors,thesimplefactthatUNforceshadamuchsmallerand

concentratedperimetertodefendwithinteriorlinesofcommunicationand

increasingtrooplevelsrelativetotheirNKPAenemies,allowedforthesuccessful

defenseofthePerimeter. 58Thispaperlinkslogisticstothesmallerlinebecausethis

muchmorecompactandmoreeasilycontrolledperimeterenabledUNforcesto

pourtroopsandequipmentintotheportofPusanmoreeasilyandincreased

logisticaleffectivenessmorethanbeforethePerimeterwasestablished.Interior

lines,consideredtobeoftheutmostimportancebyJomini,werealsomoreeasily

maintainedinthesmallerPerimeter.KoreanWarscholarsAllanMillett,Roy

ApplemanandT.E.Fehrenbachallrecognizethesignificanceofthesmallerfrontas

atleastapartialexplanationforthesuccessfuldefenseofthePerimeter.Appleman

writes:

However,withtheestablishmentofthePusanPerimeterinAugust,theUN

troopsheldacontinuouslinewhichtheNorthKoreanscouldnotflank,andtheir

advantagesinnumbersdecreaseddailyasthesuperiorUNlogisticalsystembroughtin

moretroopsandsuppliestotheUNarmy.59

ThispointbyApplemanistwofold,includingboththesmallerlineandthe

increasingtrooplevels.Consideringtrooplevelsfirst,Figure5belowshowsaside-

by-sidecomparisonofUNandNKPAtroopsasof1September1950tofurther

illustratethispoint.60

58Appleman, North to the Yalu, p. 39359Ibid. 39360Appleman, North to the Yalu, p. 382 and 395 (Figure 4)


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UNtroops,1September1950NKPAtroops,1September1950

FromthischartwecanseethenumericaladvantageheldbyUNtroopsasof1

September.

IfwecombinethenumericaladvantageswithApplemanssecondpointabout

acontinuouslinethatcouldnotbeflankedbytheNKPA,thearithmeticargument

beginstogainsteam.Everincreasingtrooplevels,crammedintoamuchsmaller

defensivePerimeterthatcouldnotbeflankedincreasestheconcentrationofforces

alongthePerimeter,andmakesafrontalassaultmuchhardertoaccomplish.

Figure5:Totalsat

topofChart


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FehrenbacheloquentlyarticulatesthischallengetotheNKPAinThisKindof

Waronpage138:InpushingtheAmericansintoacorner,theNKPAprobablymade

itsgreatesttacticalerrorithadpooroddsofsmashingtheAmericanswithdirect

hammerblows.61ThesametacticsthatNKPAcommandershadusedtopushthe

ROKandU.S.forcestoPusannolongerworked,andasaresult,NKPAforceshadto

switchtotheunappealingandultimatelyineffectivedirectfrontalattack.62

Applemanironicallyalsopresentstheonlysubstantivechallengetothe

arithmeticargument.Onpage466ofSouthtotheNaktong,NorthtotheYalu,he

discussesthefatalweaknessoftheNKPAasnotbeingabletoexploit

breakthroughsinthelineratherthananinabilitytobreakthroughatall.63Ifthe

NKPAwasabletobreakthroughatall,thenthisrulesthearithmeticargumentoutas

thesoleexplanatoryfactorinthesuccessfuldefenseofthePerimeterandsuggests

thatthereareotherfactorsthatmustbecombinedwiththearithmeticargumentto

havedecisiveexplanatorypower.

5)TheFrictionofWar

Thefinalpotentialfactorthatexplainsthesuccessfuldefenseofthe

perimeterisoneadvancedbyCarlVonClausewitzinChapterVIIofhisfamous

manuscript,OnWar.64KnownastheFrictionofWarconcept,Clausewitz

describesmilitaryforcesandoperationsasmuchdifferentonpaperthanin

actuality.Theunaccountedandunexpectedphysicalandmentaltollthatanarmy

incursovertimeandthedeterioratingeffectofmovingandfightingonmenand

equipmentledClausewitztoconcludethatthedefensewasdominate,allother

thingsequal.65Inaddition,theNKPAextendedandstraineditssupplylinesasit

continueditsadvancedownthePeninsula.EverymiletheNKPAtraveledwas

61

Fehrenbach, This Kind of War, 13862

Ibid. 13863Appleman, North to the Yalu, p. 46664Patrick M. Cronin, Clausewitz Condensed, Air War College Nonresident Studies,


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anothermilethatexacerbatedthelogisticalchallengeofresupplyandanothermile

offrictionactingagainstNKPAefforts.

Althoughwrittenmorethan100yearsbeforetheKoreanConflict,one

compellinglineofargumentexplainingthefailuretopenetratethePusanPerimeter

isthefrictionconceptappliedtotheKoreanWar.Althoughnoneofthescholarsthat

havebeenreferencedexplicitlymentionClausewitzianfriction,Applemanand

Fehrenbachbothmakepointsthatsupportthisargument.Fehrenbachdescribes

howbylateAugust,NKPAforcescombatefficiencywaslowerthanatanyprevious

timeinthewarandithadlostmuchofitsmilitaryequipmentsuchastanks,artillery

andveteransoldiers.66SimilarlyApplemanwrites,BytheendofAugusttheNorth

Koreantroopshadbeenpushedbeyondtheirlimitsandmanyoftheoriginalunits

wereatfarreducedstrengthandeffectiveness.67

ItispossiblethattheNKPAsimplyjustranoutofsteam,andthedrivefrom

the38thparallelandthesubsequentslowingoftheirmomentumafterthePusan

Perimeterwasestablishedpreventedanylegitimateshotatvictory.Asthebalance

oftroopsswungintheUNsfavorduringtheBattleofPusanPerimeter,their

(NKPA)advantagesinnumbersdecreaseddaily 68anditbecameonlyamatterof

timebeforetheNorthKoreaneffortcollapsed.Thelossofmen,extendedsupply

lines,breakdownofequipmentandthemanyotheruncontrollableimpactsofwar

thatcomprisefrictionwerecombinedwithanincreasinglystubborndefenseby

ROKandAmericansoldiersandstymiedtheNorthKoreanadvance.Accordingto

theargument,bythetimetheNKPAhadbeguntheiroffensivesonthePerimeter

theysimplydidnthaveenoughgasleftinthetaketoreallytakeadvantageofany

minorpuncturesintheline.

Figure6showsared-bluebreakdownoftheperimeter,andeventhough

NKPAforcesappeartohavearoughparityinthenumberofunitsalongthefront,

theactualnumbersofcapablesoldiershaddiminishedgreatly.AccordingtoT.E.

66


Appleman, North to the Yalu, p. 39368

Ibid. 393


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Fehrenbach,whenthePerimeterwasestablishedaround1AugusttheNKPAhad

alreadysustained60,000casualtiesmostlyatthehandsoftheROK.69By5August,

manyoftheNKPAsunitswereathalfstrengthandits11divisionsprobablydidnot

havemorethan70,000troopsaltogether.70Also,significantly,theNKPAdidnot

havemorethan40tanksby4August. 71Afteramonthoffightingandslowresupply

andreinforcement,theNKPAwasmorethanundermannedcomparedtotherapidly

growingUNforce.

AtthetimeoftheGreatNaktongOffensivewhichbeganaround1September,

theNKPAhad13infantrydivisions(5,000-9,000meneach),1armoreddivision

(1,000men),and2armoredbrigades(500meneach). 72100newT-34tankshad

arrivedandtheNKPAwasabletomuster98,000troopstotal.73Comparethese

figureswiththe500Americantanksand180,000fightingmenontheUNside,and

theeffectsofattritionbecomeclear.74

69Fehrenbach, This Kind of War, 11370Ibid. 11371Ibid, 11372Ibid. 13973Ibid. 13974Ibid 113


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75

Anotherpieceofevidencesupportingthisargumentistherapidityofthe

successoftheInchonInvasion.AlthoughInchonwasastrategicsurprise,onewould

stillexpectmoreofaresistancefromNKPAforces.Instead,theywererapidly

drivenuptotheYaluwithinafewmonths,suggestingbythistimethattheir

75Lynn Montross and Captain Nicholas A. Canzona, The Pusan Perimeter: Volume 1,(Washington, D.C., USMC G-3,1954). Inside Cover

Figure6


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offensiveandthesubsequentstalemateatPusanhadtakensuchatollontheir

combateffectivenessthatastubbornresistancewasnotpossible.76

Again,onesalientchallengetothisargumentishowclosetheNKPAcameto

breachingthePusanPerimeter.Fehrenbachwentsofarastosay,Forthirtydays

theoutcomewouldhangbyaslenderthread77Itwouldseemthatifthefrictionof

warwasthedecisivefactor,theoutcomeofthebattlewouldnothavebeenso

ambiguousthroughoutitsconduct.Inspiteofthischallenge,thelogicandevidence

presentedsuggestsfrictionhadasignificantimpact.

ASynthesisofArguments

Fromtheaboveanalysisitisclearthattherewasnosinglefactorthattipped

thebalanceonewayortheotherandthatthedefenseofthePerimeterwasmoreof

aresultofasynthesisoffactors.Thequestionis,whichfactorswerethemost

importantcontributorstotheUNdefenseofthePerimeterandthefailedNorth

Koreanoffensive?

Simplybasedonthestrengthoftheargumentspresentedandwhetherthe

evidenceexaminedseriouslychallengedthevariousconclusions,therearethree

factorsthatappeartohavethemostexplanatorypowerintheholdingofthe

Perimeter.First,Americanfirepowerwasanessentialcomponentofslowingthe

NKPAsadvanceandsupportingthedefenseofthePerimeterinplaceofthelackof

artillery.ThetechnologicaladvantageofSIGINTalsoprovidedtheUNwithbetter

intelligencetoredistributeitsforcestodangerspots.Second,thearithmetic

componentofasmallerPerimetercombinedwithincreasingtroopnumbersand

easierlogisticaloperationswereproblematicfortheNKPAbecausetheirearlier

tacticsofflankingandexploitingwerenolongereffective.Asresourcesandsoldiers

pouredintoPusan,theNKPAhadmoreofanuphillbattleaseachdaypassed.

Finally,thefrictionofwarargumenthelpsexplainthestalledNKPAadvanceandthe

76Appleman, North to the Yalu, 729-745.77



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failuretoexploitanyminorpuncturesinthePusanPerimeter.Thelongfightthat

ledtothePusanPerimetertookatollontheNKPA,andwhenitcametimetomount

anaggressiveoffensiveandexploitsuccesses,theresourcesandmanpower

requiredweresimplynotthere.

4.TheSignificanceoftheDefenseofthePerimeter

TheSignificancetotheKoreanWar

ThedefenseofPusanisoneofthemostremarkableeventsofthewar

becauseitpreventedthecompletecollapseoftheROKandthedominationofthe

Koreanpeninsulabythenorth.Unquestionably,hadNKPAforcessuccessfully

penetratedtheperimeterandcapturedPusanthewarwouldhaveturnedoutmuch

differently.ItisalmostcertainthattheROKmilitarywouldhavecollapsedinthe

eventofaNKPAvictoryatPusan.WhethertheROKgovernmentcouldhave

survivedinexile,aUNcoalitionwouldstillhaveintervenedandinvadedthe

Peninsula,ortheNKPAwouldeventuallystillbedefeatedinanattacksimilarto

Inchonareallcounterfactualsoutsideofthescopeofthispaper.Whatisclearata

minimumisthattheoutcomeofthewarwouldhavebeenradicallydifferentandin

alllikelihoodwouldhaveturnedoutworseforUNforcesthaniteventuallydid.The

ceasefireof1953,althoughbynomeansdecisiveineitherdirection,preservedthe

statusquoofthewarandinthatsense,theUNcoalitionaccomplisheditsmajorgoal.

TheSignificancetotheColdWar

ThesignificanceofthesuccessfuldefenseofthePusanPerimetertothe

KoreanWarismuchmoreobviousandconcretethanthemoreglobalColdWarimplicationsofthisvictory.IfweconcludethatthedefenseofPusanwascriticalin

thepreservationoftheROKatleastintheshortterm,thenitislogicaltoconclude

thattherewereglobalimplicationstothissuccess.Anyconclusionsdrawnhereare


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largelyspeculative,butnonethelessgroundedinlogicandhistoryasaguidefor

whatmighthavehappened.

HadtheNKPAtakenPusanandineffect,thewholePeninsulaandtheUNhad

notintervened,theUnitedStateswouldhavelostacriticalstrategiclocationinEast

AsiaontheheelsoftheCommunisttakeoverofChinain1949.Ifbothofthese

eventshadoccurred,theUnitedStatesstrategicpositioninAsiaduringtheColdWar

wouldhavebeenincrediblydebilitated.TheUnitedStateshasmaintainedandstill

maintainsastrongmilitarypresenceinSouthKorea,andmilitaryforcesinthis

nationwereacorecomponentoftheU.S.AsianpresencetohedgeagainstSoviet

threatsinAsia.

HadtheNKPAtakenPusanandtheUN hadintervened,thelossoflifewould

havealmostcertainlybeenmuchgreaterthanwasactuallythecase,whichisa

significantimpactinitsownright.Theamountofresources,equipmentand

manpowerthatwouldhavebeenrequiredtoretakethepeninsulawithnoinitial

friendlylandingzonewouldhavealsobeentremendous.

Forthesereasons,thedefenseoftheperimeterwasacrucialeventbothin

thewarandinthebroaderstrategicenvironmentoftheColdWar.

5.Conclusions

Thispaperhaspresentedanargumentfortheprinciplefactorsthat

contributedtothesuccessfuldefenseofthePusanPerimeterduringtheKoreanWar.

AfterdiscussingthecontextandoverviewoftheKoreanWarandtheBattleofPusan

Perimeter,thispaperpresented5possiblefactorsforthesuccessfulUNdefenseand

failedNKPAattackofthePusanPerimeter:1)NKPAlogisticalineffectivenessasa

resultofU.S.airpowerandinherentNKPAlogisticaldeficiencies,2)NKPAmilitaryineptitude,3)superiorUNfirepowerandtechnologyalongthefront,4)asmaller

fronttodefendwithbetterlogisticsandincreasingmanpowerand5)thefrictionof

war.Throughananalysisofeachofthesefactorsbyexaminingthelogicand

evidenceofeachexplanation,thispaperconcludedthatacombinationofsuperior


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firepowerandtechnology,asmallerfrontwithbetterlogistics(andmanpower)and

thefrictionofwararethethreemostexplanatoryfactorsforwhytheUNwas

successfulinitsdefenseofthePusanPerimeter.

ThispaperthenexaminedtheimplicationsoftheUNvictoryatPusanforthe

Koreanwarasawhole,concludingthatataminimumitpreventedthecollapseof

theRKOmilitary,andledtoamoreacceptableconclusionofthewarforUNforces.

ThispaperalsoexaminedtheimplicationsfortheColdWarasawhole,speculating

thathadUNforceslostatPusanandtheentirePeninsulawastakenbythenorth,

therewouldhavebeenanegativeimpactontheUSstrategicpositioninAsiaduring

theColdWarandthepotentialforamuchgreaterlossoflifeiftheUNconductedan

invasiontoretakethePeninsula.


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B.H.LiddellHart,DeterrentorDefense,(NewYork,NY:FrederickA.Praeger,Inc.

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EdwinP.Hoyt,ThePusanPerimeter,Korea,1950,(BriarcliffManor,NY:SteinandDayPublishers,1984).

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KennethW.Estes,IntotheBreachatPusan,(Norman,OK:UniversityofOklahomaPress:2012).

LynnMontrossandCaptainNicholasA.Canzona,ThePusanPerimeter:Volume1,(Washington,D.C.,USMCG-3,1954)

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RusselA.Gugeler,CombatActionsinKorea,(WashingtonDC:CenterofMilitaryHistory,USArmy,1987).

T.R.Fehrenbach,ThisKindofWar,TheClassicKoreanWarHistory,(WashingtonDC:Brasseysinc.,1963).

T.R.Fehrenbach,TheFightforKorea,(NewYork,NY:GrossetandDunlap,1969).

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PressofthePacific2005).

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The Decisive Factors in the UN Forces’ Defense of the Pusan Perimeter in 1950 Korean War

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