MH-18: Victory in the Pacific

MH-18: Victory in the Pacific

MH-18: Pacific Victory - Strategic OverviewNaval & Amphibious War – Operational Level • US Grand Strategy: still Germany “first” => but… • political reality could not be ignored: • Japan bombed US first at Pearl Harbor • American Public demanded revenge on Japan • Result => Grand Strategic objectives & priorities adjusted: • Pacific theater gets higher political & military priority • Also: setting strategic priorities forced leadership: • Allocate scarce resources among competing CINCs • (i.e. forces, logistics and supplies) • Not => best strategic objective or COAto pursue (CINC personalities) • Result: logistics and politicalconsiderations drive=> • Allied Strategy => producing ad hoc strategic approach => • “Dueling” operational strategies in Central & SW Pacific • US called them “complementing strategies;” Brits called them competing

Strategic Opportunity vs. Limited Resources • Following Battle of Midway (June 1942)=> • CINCPAC (Nimitz) still left with only limited resources • A Major limitation for prosecuting war in Pacific theater • Only able to assign 1 UMSC division to secure Guadalcanal • PACFLT ships barely able to protect Australian LOCs • Later US mobilization expanded MPN & logistics=> • Made sufficient forces available to Pacific (by latter half of war) • Enabled US to pursue & adequately support: • 2 separate pronged strategies led by MacArthur (SW) & Nimitz (Central) • As Pacific War was fought => • Number of ships sunk surpassed all previous conflicts • Combined Air/Sea/Landops accelerated toward the War’s end • But what would finally put an end to the war with Japan?

South Pacific (August’42-December’43)Guadalcanal • Navy & USMC conducted operations in South Pacific => • Specifically in the Solomon Islands=> at Guadalcanal • USMC continued to defend against escalating assaults • Japanese conducted wave upon wave of frontal assaults • Suffered horrendous casualties in process • 15K killed or missing – 9K from disease - 1000 captured • Meanwhile=> Naval battles also fought throughout • Conducted in & around Solomon Islands (Salvo Island- USN defeated)

Operation Cartwheel • Series of battles then conducted in parallel in SW Pacific • Background: • CasablancaConferenceof Jan 1943 • Key issue: unity of command in Pacific Theater: • Army (MacArthur)versus • Navy (Nimitz) • Question: who’s in charge & whose strategy will prevail: • (i.e. Given priority for resources & manpower) • Macarthur’s proposed strategy? • Capture?______________in 1943 • CJCS response? • Too ?__________ & ?__________

Fallback Strategy • CJCS Compromise: • 2 pronged drive converging on Rabaul • Tactical objective: capture orisolateRabaul • Concept of Operations(Map): • “Bull” Halsey to advance up Solomonsto Bougainville • MacArthur advance along New Guineaeast coast • Attack New Britain • Then isolate Rabaul • Significance? • PACFLTemployed to meet political objectives (PHrevenge) • Cartwheelalsowould become model for entire Pacific campaign

Air Power’s Rolein SW Pacific • Key role in Cartwheel & future Leap-frog strategy • Employ CAS for invasion=> troops establish runways=> • Used as FOB & Air Field to attack next island target • Then US starts the cycle over again for next “Islandleap” • MacArthur’s top air commander & strategist • MG George C. Kenney • Developed new & innovative tactics • What kind of innovative tactics? • Employed land based air to strike Navy & defenses • Modified B-25s w/8 50 cal MGs in nose • B-25s fly low level sorties against ships • Skip 100# bombs into enemy shipping • Big improvement over past USAAF ops against Japanese ships

Japanese Response – April 1943 • Japanese successfully deploy 8th , 17th, & 18th Armies to SW area of operations from China & Japan • Then re-deploy 51st division from Rabaul to New Guinea • Magic forewarns allies of Japanese intent: • Battle of Bismarck Sea • MG Kenny’s modified B-25s make low level & B-17smake high levelattacks • Land based Air destroys Japanese troop transports for decisive Allied victory • Impact: loss of this huge armada, loaded with supplies and troops, ended Japanese hopes of retaining control of New Guinea • Also gains US Navy’s reluctant recognition of new Air Force (AF) tactic • Magicalso alerts allies of AdmiralYamamoto’s planned air trip: • Action taken by allies?

Amphibious Campaign- Island hopping • Macarthur & Halsey continue duel advance: • Conduct amphibious landings or isolate enemy at: • New Georgia, Bougainville, New Britain, etc. • Tactical & Operational objectives & strategy: • Capture Japanese built air fields (or build them on captured Island) • Occupy & stage for further advance up island chain • Skip & isolate heavily defended island defenses: • Close off enemy’s LOC instead (Illustrated byKolombangara) • Capture more air strips & “island hop” all the wayto Japan

SW Pacific “Island Hopping:” Results & Significance: • Each seized island provided air/logistic base for next hop • Isolated Japanese units died on vine => • Therefore it presented no more operational threat • Useful precedence established: • Successful operational strategy was used throughout rest of war for entire Pacific Theater • Allied buildup in Pacific & air/sea control enhanced • Success encouraged more support & higher priority

Central Pacific Campaign (Nov’43-Feb’44)Strategic Aims for Pacific • Trident Conference (Washington DC- May’43) • FDR, Churchill, & CJCS establish strategic aims for Pacific Theater • Strategic aims included: • 1. Cut off Japanese raw materials • 2. Conduct strategic bombing on Japan • 3. InvadeJapan home islands & destroy military power • Operational Strategy: • Build on success in Burma, So. Pacific, China=> • Then launch strike against Japan itself

Concept of Operations:Two Opposing Concepts • 1. Drive across central Pacific • (who’s proposal?): • Use Coral Atolls for launch sites (logistics, FOB staging, etc) • 2. Continue drive in So Pacific via New Guinea & PI (who?) • (“I shall return”) • But he needs Naval support in order to accomplish this concept • South Pacific Strategy- Halsey’s role (“MacArthur’s Admiral”) • CJCS compromise? • Balance two strategies – • Complimentary? • ADM King’s proposal modified– how? • Strategies converged where? _______________ • To provide Sealift for MacArthur’s “return” ADM King

Navy’s Key Role- Sea PowerPACFLT Order of Battle • US shipbuildingon step by Summer’43: • Major positive impact on US Order of Battle • Essex class Fleet Carrier (CV): 27K tons & 100 A/C • Independence class light Carrier: 11K tons & 50 A/C • CV aircraft: F6F Hellcat • Commander 5th Fleet (Spruance) forces comprised: • 6 Flt CVs, 5 lite CVs, 12 BBs, 9 heavy & 5 lite CRs + • 56 DDs & required support: Oil, Ammo, Supply ships • Submarines had a special role*

Submarine Campaign- Pacific Most effective offense throughout Pacific: Submarine (SS) attack on Japanese commerce Slow start at beginning due to number of reasons Lack of leadership & tactical skill (peacetime COs) Faulty torpedoes & denial of problem at BUWEPS Resulting in self destruction of USS Tang Once solved => Japanese Navy & merchants very vulnerable: Japanese conducted no serious prep against SS threat Prior to & during early part of War No adequate staff or command level attention devoted No convoy system developed or anti-SS resources When problem finally recognized => too late 14

“Sustained Combat Operations at Sea” • PACFLT dominated seas in & around Japan by Fall’43 • USN Capacity & capability unsurpassed • Logistics, re-supply, & repair at sea unmatched • 5th & 3rd Fleet HQ staffs simply rotated • The Fleet itself was always at sea • HQ ashore planned for upcoming operations • Japan simply could not compete at this level • Fleetable to conduct opposed amphibious landings • Protect landing forces with air & sea power • Fleet also able to conduct major surface battles (CV air) • All the while remaining at sea indefinitely • Many sailors stayed at sea almost entire war

Central Pacific Strategy • The drive through the Central Pacific given higher priority • Especially by the Navy leadership & many members of CJCS • SW Pacific drive seen by many as based more on “political” considerations than strategic or operational priorities • (FDR wanted to keep MacArthur as far away from Washington as possible)

Tarawa (Nov’43)- Objectives • Tactical & Operational Objectives: • Gilbert Islands were 1st objective of Central Pacific Drivestrategy • Target: Betio in Tarawa atoll • Battlefield preparation: • Inadequate NGF support • Poor recon (Photo from air) • Lack of critical Hydrographic Reconnaissance data • Reef ½ mile out from landing beach would block landing craft • Marines must wade ashore

Tarawa: Execution • Lack of sufficient gunfire support & preparation = high casualties • Lack of proper coordination between landing force & sea commanders • USMC landing force come ashore to kill zone wading in head+ high water • Planners grossly underestimated enemy strength & defense • 5000 Japanese troops dug in with heavy weapons- pour it on Marines • Serious lack of adequate information about beach landing site: • Coral reefs ground landing craft far off shore • 2nd USMC forced to wade ashore – many drown w/heavy equipment & ammo • 5000 finally make it ashore through heavy fire, but 1500 are dead or wounded

Tarawa: Results • Bitter lessons learned • Casualties: USMC: 3381 (990 KIAs) out of 18,600 • 4Medal of Honors (MOH) awarded • (3 post humorously) • Japanese: 17 survivors out 5000 man garrison • PACFLT concluded better & more up close hydrographic recons required prior to future amphibious landings • Underwater Demolition Teams(UDT) reason for being: • Reconnaissance & demolition

Central Pacific Drive Continued • USN next month op was success: • Isolation of Truk(750 due west) • Precludes Truk’s use by Japanese Air Craft • Unable to stop US invasion of Eniwetok- Feb 44: • Luck: early US attack prevented Eniwetok adequate defense • Result: USMC lives saved due to earlier Feb assault • Eniwetok’s capture => Operational impact: • US now 1000 miles west of Tarawa: • Closer to next operational objective: Mariana atolls • Also 1000 miles closer to US strategic Objective: (what?) • ?________- US to use Marianas as air base to bomb ?_________________

SW Pacific Operations Linked to Central Pacific • Two separate Pacific Drives continued • Mac isolated Rabaul & then seized Hollandia • Wakde & Biaksoon taken after Hollandia • Wakde & Biak’sOperational significance? • Within range of PI with American Aircraft • Japanesealso realize the significance of threat • Impact of friction & good timing: • Macarthur’sluck holds at Biak • Spruance (5Flt) attacks Marianas • Japanese immediately cancelled attack on BiakIsland (never to return) • Prepare to deploy Task Force to Central Pacific • Spruance’s attack in Central Pacific sets in motion new Japanese Operation: “A-GO” • Tactical Objective: • Decisive Battle in Central Pacific to destroy PACFLT’s 5th Fleet

Central Pacific => The MarianasSaipan, Tinian & Guam • Saipan - closest major Island in the Marianas: • USMC 2nd & 4th divisions tasked to take Saipan • Army 27th ID in support • Also tasked to take Tinian following Saipan • Saipanwas defended by 32K Japanese • (but its defense preparations were incomplete & soon fell) • Op. & Strategic significance? • Saipan is now within B-29 range • US secured Tinian & Guam by July & early Aug after hard fighting

Battle of PI Sea • Spruance’s advance on Marianas & attack on Saipan has major impact on Japanese strategy • Forces Japan to dump Biak& establish 1st Mobile Flt: • 1st Mobile Flt comprises: • 9 CVs w/400 AC, 5 BB, 13 CR, 28 DDs • All units re-deployed to Central Pacific • Tactical & Operational Objective: • DestroyAmerican 5th Fleet • Spruance kept Fleet between Saipan amphibious ops & Japan’s Fleet • Japan forced to attack=> 4 waves of 373 AC strike (only 100 penetrate CAP) • TF58A/Csink one CV & damage 3 others (US SS also sink 2 CVs) • Result: Although bulk of Japanese Fleet escapes: • Battle has big Operational impact on Japan-what? • Major loss of ?_________ __________ ________ _______________ • USN Fleet structure/coordination & power projection validated

Philippine Invasion • King & MacArthur disagree over final operational strategy of Pacific war • King wants to continue island hop to Mindanao • (in Southern Philippines) • Then to make big jump to Formosa & China Coast (Map) • This is here “scouts & raiders” have reconned potential beach landing sites in China • FutureFOBs for Japan’s invasion • MacArthur continues to press for liberation of PI people

Leyte Gulf -Oct 44- July 45 • Convergence to 2 prong drives=> both toward ?___________________ • Key stepping stone to Luzon (main PI island) • Key events: Halsey conducts engagements off to east of PI • Destroyed much of Japanese land and CV basedaircraft • Forced Japanese to return to Japan for repairs & replace pilots • Halsey deduced that Japan lacked strong force in PI (wrong) • Japanese prepared for decisive battle with complex plan: • 4 separate TF to attack US force in waters off PI • CVs from Japan to draw US CVs away from Luzon • Surface Flt (BBs) to move through San Bernadino Strait: • Tactical objective: attack US landing forces landing at Luzon • Remaining Japanese TFto move thru Surigao Straits

Leyte Gulf:Execution • Oct 20: MacArthur attacks NE coast of Leytewith LTG Krueger’s6th Army • Encounters moderate resistance but 6th Army fights inland • Japanese respond but are spotted by US submarine • US Navy attacks & sinks 2 heavy Japanese cruisers: • This rattles Adm Kurita, Commander of main San Bernadino Task Force • Japanese A/C from Leyte attack Halsey (Princeton is badlyt hit) • But Halsey’s A/C find Kurita’s TF & attacks: • Sink super BB Musashi • Kuritabecomes even more rattled & retreats from PI

Halsey’s Blunder • Halsey sails entire Fleet North in search of more targets • Leaves nothing behind to defend Amphibious ships! • Meanwhile Imperial HQ ordered Kuritato return to fight: • Kurita now unopposed for transit of San Bernie Strait • Only few DDs & escort CVs between him & what? • ?_______ ________ _______! • But still able to harass enemy & prompt Kurita’s withdrawal • Very close to disaster for Americans (& Halsey’s reputation) • By Christmas last Leyte port taken* by 6th Army- mop up ops follow

Ominous New Tactic Revealed • Ominous new tactic makes its debut at Leyte Gulf: • A serious new threat used against US in future battles • What is the new tactic used by Japan near end of war as a last resort? • ?_____________ ____________ • Japan strips all available forces to reinforce Leyte • Taken from Luzon & Okinawa • Major future impact later

Luzon -Jan 45 • MacArthur finally fulfills his promise to return • Navy pays dearly price in process => why? • ?_________________ attacks on USN • Meanwhile GeneralYamashita abandons cities for mountain defense • 6 Jan: 6th army lands on Lingayen Gulf: • 4 infantry divisions => total of 175K men • 6th Armymarches 40 mile in 2 weeks thru light resistance • 29 Jan US makes 2 more landings: • NW & SW of Manila • Though Yamashitaordered cities abandon => • Japanese Marines fight on to keep Manila • (Not in his Chain of Command) • Manila virtually destroyed as result - 100K civilians die & Yamashita is blamed for it • And subsequently tried and executed for it

Final Campaigns- Iwo Jima (Feb-Jun’45) • Background: • Operational significance of Iwo: Japan’s early warning • Also Japanese fighters based on Iwo harass B-29s • B-29s conducting bombing raids from Marianas • Suffer heavy losses without much to show for it • Also emergency landing field badly needed upon return flights • Order of Battle: • Japan: LTG Tadamichi commands 21K with 1000 guns • Strong defensive positions: dug in deep in caves and tunnels • US: VADM Turner commands Joint Expedition force • LTG Holland Smith commands Troops: USMC V corps • Comprised of: 3rd, 4th, & 5th Marine divisions • Armored amphibian tractors & Navy NFS

Iwo Jima-Plans & Objectives • Strategic, Operational, tactical Objectives: • Japan: defend Iwo & prevent its capture • US: capture Iwo & use for B-29 emergency landings • Concept of Operations: • Japan: defend fm complex system of caves & tunnels • US: attack abreast on SW beach=> main effort to south • Iwo Battlefield preparation: • Japan: withdraw to mountain areas & await attack • US: Recon beach landing areas & NGF prep

Iwo Jima-Execution • 0935 19 Feb: 1st wave of armored tractors insert • 5th Div on left & 4th Div on the right (Map) • On left 28th infantry regiment turns South to Suribachi • Gains crest after 4 days of heavy fighting (plants American flag) • Main effort to North – slow advance of 5th & 4th Divs • Japanese conduct fierce resistance all along (red) defense lines from tunnel/ & cave network • Island finally secured after heavy fighting on 26 March 1945

Iwo Jima- Results • USMC: • 5931 KIA/17372 WIA out of 71245 put ashore • (27 MOHs awarded – half post-humorously) • Japan: almost all defenders killed • 216 POW survivors taken (Korean civilian contractors) • US eliminatedfighter threat to B-29 raids on Japan • Emergency landing field secured • 2251 heavy bombers (B-29s) & crews saved from ditching • 24761 total made emergency landings on Iwo Jims airfields

Okinawa (April – Jun 1945) • Background: • Final land battle of the Pacific war • Capture would provide a staging base for air strikes and invasion • Order of Battle: • Japan: LTG Ushijima commands 32nd Army (77K) • Plus 23K Navy and Oki conscripts = total: 100K • US: ADM Nimitz overall Theater commander- ADM Spruance, CMDR 5th Fleet w/1200 ships • LTC Buckner: 10th Army (III & XXIV corps) 182K

Okinawa: Plans & Objectives • Strategic, Operational, tactical Objectives: • Japan: prevent capture of Oki as long as possible: • Inflict maximum casualties on assaulters • US: Capture Oki & use it as base to stage invasion of Japan • Concept of Operations: • Japan: defense in depth with main strength to South: • 3 major defense lines following E-W ridge lines • US: Land III & XXIV Corps & attack defense lines to North & South

Execution – Easter Sunday-1945 • US: After heavy NGS bombardment, land 2 corps (2 div each) on west side • III corps proceeds to left & XXIV to right • Marines turn North & Army south into 1st defense line • Ushijimadelays counterattack until 12 April: • Awaited massive air-sea attacks on 5th Fleet • Counterattack easily absorbed by XXIV • MeanwhileIII corps overran most of central & North Okinawa • Buckner shifts portions of III Corps to southern engagement

Final Assault & Results • 18 June Buckner launches final assault on 3rd line: • Buckner is killed by Japanese shell • III corps commander takes over • Declares Oki secure on 21 June 1945 • Throughout numerous Kamikazeattacks conducted on the Fleet • Launched in 10 major waves severely damage fleet • Last wave launched on 22 June • Results: • Okinawa secured for base of operations for Allied invasion of Japan • Casualties: • 10th Army: 7613 KIA/31800 WIA • Kamikazes sink30 ships/damage 365 + 5K KIA • Japanese: 142K+ • (including Oki civilians)

Japan Under Siege • Following establishment of base at Okinawa, Japan constantly under attack from air and sea • Duration: June-August 1945 • The greatest direct impact came from land and sea based air • Curtis LeMay => introduces new Air Force tactic => • From precision bombing to incendiary area bombing • Conducts low altitude night attacks (like RAF)

Strategic Bombing • Strategic air campaign intensifies from Oct 1944 to Aug 1945 • Tokyo fire storm kills 83K civilians; • Japan prepares to resist to end: • Prepares up to 5K Kamikazeplanes & pilots (300-400 launched/hour) • Also suicide speed boats with high explosives • US planned amphibious landing at Kyushu • Estimated casualties for invasion force => 700K!

Manhattan Project • Meantime Manhattan project successful • Proves feasible by summer of 1945 • VP Truman succeeds FDR upon his death=> • Then informed for first time of Atomic Bomb weapon • Truman decides to use it on Japan: • On 6Aub45=> B-29 drops first Atomic Bomb over Hiroshima • 90K people die in huge blast • 3 days later => same thing over Nagasaki • The atomic genie is now out of the bottle!

Japan Surrenders • Japan’s responseto Atom Bomb: • Japanese cabinet argued no such weapon exists until Nagasaki • Remained deadlocked over surrender • Emperor steps in and orders Japan’s surrender • Conditioned on his remaining in ceremonial position • Japan surrenders (Sept 2,1945): • Japan’s delegation sign surrender instrument: • Signed aboard USS Missouri (MacArthur presiding)

World War II- Assessment • WW2 most destructive war in human history: • Cold War begins with A-Bomb always in shadows • War finally ended Hitler’s threat of world domination • Along w/Mussolini & Japan’s Imp Gov • From a tactical & operational perspective: • WW2 restored tactical & Op mobility to Battlefield • Tanks, A/C, ABN units integrated & employed for land warfare • Carrier Air for war at sea • Amphibious operations for power projection: • Island Hopping strategy in SW & Central Pacific • Amphibious Ops at great distances in Central pacific • Logistics/supply system allowed nonstop deployed Fleet

Assessment-2 • New technology & weapon enhancements: • Radar/Sonar & submarine warfare proved effective: • Enhanced Interdiction & protection of SLOC • Improved C3I & better operational control & coordination • Superior allied Intel collection & analysis (Ultra & Magic): • Deception & perception management • All gave distinct advantage to allies • Superior command, control, & communications: • effective integration/coordination of allair/sea/land => • directed forces together toward common op. purpose • Superior mobilization of industrial might: • all above supported by unmatched Log system & MPN • War economy & industrial capacity & vast available MPN • All effectively directed toward national objectives

Assessment-3 • WW2 continued WW1’s tactical develop & op concepts: • Evolutionary process of improvement & refinement for: • Blitzkrieg w/tanks; • strategic bombing; • submarine warfare; • Amphibious doctrine (w L/L) • In contrast to WWI: • Destruction was much greater scale (civilian & property) • Holocaust & Nazi atrocities shocking • Strategic bombing killed 100ks- cities/civilian population • Atomic bomb => Nuclear weapons => MAD Cold War strategy of 20th cent. • Post WWII Cold War would make world bipolar • West versus East Europe divided world following WWII • NATO versus Warsaw Pact • Democracy & capitalism vs. Soviet dominated Communism • War also ended or soon ended Western Empires • NTL: relative peace (i.e. no world wars) to present • Although certainly “a hard and bitter peace” followed- JFK

Backup Slides (The Details)

Two separate Pacific Drives- continue (1943-44) • British question efficiency of Two Drive Strategy- (why?) • US response? • Both drives mutually supporting? • Real reason? • (Macarthur vs King & Nimitz) • Brits response: mutually competing (scarce resources) • Macarthur’s advance in South West Pacific- (Map): • Op Objective: Philippines (leap frog over hard points) • Establish air strips for fighter escorted bombers => • Protect & further advance west

Papua • Order of Battle: • Australian 7th & US 32nd Divisions • Japan: 11K on New Guinea • Macarthur’s operational objective & strategy: • Defend & protect Australia & its LOCs • Control New Guinea • Deny secure Japanese basing in SW Pacific

PapuaExecution: • MacArthur deployed US & Australian forces to Port Moresby • Then attacked Buna(where allies get bogged down) • MacArthur becomes impatient with lack of progress • Sends LTG Eichelberger to fix hold up • He swiftly improves supply lines & combat power • Improves food & morale • Brings in tanks to support infantry

PapuaResults • All operational objectives gained => • US regains operational initiative: • Japanese driven from Port Moresby & US holds Guadalcanal • Buna captured within a month • Sanananda taken a month after • Several hard lessons learned WRT reducing Japanese defenses • US Casualties: 8500

SW Pacific Drive- Objectives • Two separate Pacific Drives- continued (1943-44) • In SW Theater Mac’s Op Objective: PI • Mac’s immediateobjective: isolate Rabaul & accelerate his advance • 1st Calvary Det (1000 troops) assault Admiralty islands- specifically=> Los Negroes: • (High risk op- barely in range of CAS) • Mac is lucky: defenders concentratedwhere? • East end-=> Allows US attackers time for re-enforcements => • Beat off Japan’s counter-attacks- • Hollandia (New Guinea) • The next target: • Tactical & operational objectives: • Isolate 40K more Japanese troops • Secure 3 Japan built air strips for further advances

MH-18: Victory in the Pacific