MH-15: Pacific & Atlantic Theaters

1. MH-15: Pacific & Atlantic Theaters

2. Pacific & Atlantic Wars (1941-42)Strategic Overview • When US & USSR entered WWII=> • The war became global in scale • Key challenge for US participation in war: • Mobilize & deploy its industrial might to Europe & the Pacific • To accomplish deployment of its mobilized force => • US must protect LOC to Europe • Problem & major challenge to protecting LOC? • By 1942: US able to halt Japan’s Pacific expansion –how? • US able to mobilize substantial resources; • fight and hold their own in massive battles w/Japanese • also USN addressed submarine threatby end of 1942 • Then the US turned the corner => initiated power projection German ?____ threat

3. Initial Limitations • NTL=> at start, Allied attack on Germany limited to primarily what? • Strategic Air Strikes, while… • Maintaining defensive posture in the Pacific • Allies’ primary grand military strategy? • Germany first! • Any problem with Germany first following December 7th? • US public opinion focused anger toward who? • Impact: Public Opinion forced some shift in additional assets to Pacific theater: • Divided up between what key Pacific area commanders? ?________ General ?__________ & Admiral ?_______

4. Naval War- Two key Theaters of War • Atlantic: • German SS threat: troop transport/supplyLOC • US employed convoy system and anti-SS warfare • Pacific: • Large surface engagements (primarily with CV- Air) • Pacific’s geographydictates different strategy • Primary Operational strategy:island hopping: • Land/air and sea forces required to accomplish • Gradually more & more assets shifted to Pacific

5. Pacific Theater- to 1941 • War in the Pacific - its origins? => scarce resources! • Pacific War’s Origins: • Japan’s lack of strategic natural resources => (oil & minerals) • Impact: major strain on national economy; • Further compounded by global $$$ depression of the 1930s • All taking place during growing radical nationalists sentiment • Japan’s solution to its problems: • Expansion beyond Japan seemed an obvious solution => • This attitude was shaped by growing military influence • Military controlled by extreme nationalists • Most likely target for Japan’s expansion? • NE ?__________ => easy target for expansion => Manchuria (Map) • Strategic Motive? (Manchuria is rich in coal and iron ore) • 9/16/1931: Junior Officers of Army blow up Rail line near Mukden to fabricate pretext for invasion & subsequent establishment of “Manchukuo”

6. Japan On the Move • Japanese Army conducted aggressive actions toward China: • 1937: Fabricate Marco-Polo bridge incident • Pretext for extensive intervention into China • Japan thus conducts undeclared war on China: • Occupies & controls major Chinese ports & cities • Japanese commit atrocities- especially at Nanking • Countryside remains contested – by who? • Nationalists & but especially ?_____________________ forces • Aug 1939: USSR (LTG Zhukov) defeats Japanese in 3 days at Nomonhan: • Japan learns a serious lesson • Avoid direct combat with Soviets in future • Germany failed to learn from Japan’s experience

7. US Defense Posture • US views Japanese expansion in Asia with growing alarm • American Government issues sharp protest: • Asserts Japanese actions in Chinaunacceptable: • What action does US initially take as a result? • No direct US assistance to China against Japan (rhetoric only) • US capability to back up its protest against Japan: • How prepared is US to defend interests in PACOM? • US spends token sum on defense in Asian (PI) region: • American Pacific island interests get little funding • Spring 1940=> Japan incorporates SE Asia: • Now to be part of Japan’s New Order in Pacific • Nov’40: Japan deploys troops to Indo-China • July ‘41: Japan seizes South Indo-China=> • Specifically in British & Dutch colonies in SE Asia -why? • Taken as ?_________________ position for future advances

8. Strategic Implications • Implications for US interests in Philippine Islands? • America finally realizes Japan’s potential threat-PI! • US Response: embargo oil & other exports to Japan: • Japan’s economy feels the pain – reaction? • Growing ?____________ sentiment toward US • Japan now convinced something must be done; • Nov 41: Gen ?_____ Hideki • (New nationalist Premier) talks tough & aggressively • Calls for removal of British & US influence from Far East/Pacific

9. US Strategy & contingency Plans • Early US: “color plans”=> mainly offensive operation • What was the name of the Plan for dealing with Japan? • Plan ?_______________: • US Naval strike thru Pacific=>Japan • Tactics: Big gun ships=> surface battle fleet engagements • Aimed at offensive ops to defeat Japanese Navy • Plan modification: the “Rainbowseries:” • Evolved as early planning process continued • Plans updated (late 1930s)=> for Japan:=> Rainbow ?____: • Biggest change? • Involved shift from ?__________ to ?____________ in Pacific

10. US Strategic Priorities • US (coordinating w/Brits) re-prioritize Theaters of Ops: • Germany/Italyconsidered US 1st priority • Based on Hitler’s aggressive foreign policies ambitions of 1930s • Backed by FDR (Germany on the march since 1939) • Became established Fact in May 1940 with invasion of France: • With fall of France => Britain now stood alone against Hitler • Key practicalreason for shift: • US simply unprepared for war at that time in history • Full readiness will take until 1943 to fully mobilize US industry • Complex logistic support system required for this war • Result: => priorities for war had to be re-adjusted • Problem: Rainbow 5 had aflawed planning assumption: • What was this flawed assumption in US planning?*

11. Flawed US planning assumption • Timing! • US planning assumption for Pacific: • No war in Pacific until Spring of 1942! • Plan assumed time to build up defenses in Pacific • Particularly where in western Pacific? • The?______________ Islands • US planned to conduct operations from Manila as key base of ops: • US expands number of heavy bombers & bases in PI • Use asdeterrent orcapability if requiredagainst Japan

12. Japan’s Timeline • Unfortunately for US planners, Japan had own timeline • But… Japan also has its own limitations: • Its Army was extremely provincial & short sighted • Currently Japanese Army was tied down in Manchuria • Japanese Navy had a broader strategic perspective => • For decades planned & exercised contingencies against US • Japanese peacetime Navy superior to US in most respects: • Furthermore => Japan’s pilots were unmatched in night flight ops • Long lance torpedo weapon system was the best in world • Japan’s CV capability was fully equal to US: • Though apparently not recognized by the US Navy at the time • Japan’s Grand Strategy & War Plans during late 1941?*

13. Japan’s Grand Strategy & War Plans(late 1941) • Strategic overview of Japan’s Strategy & War Plans: • Japan’s Concept of Operations: • Attack Malaya & the Philippinessimultaneously • Capture Dutch west Indies • Conduct major offensive into Burma • Capture Wake & Guam • (Cut US LOC to WESPAC) • Then establish defensive perimeter about captured area: • Invite USN to attack into the Western Pacific • Conduct SS & CV air attacks followed by => • Main Battle Fleet showdown on Japan’s terms

14. Operational Strategy • As modified by Admiral Yamamoto: • 1. Initiate surprise attack on US PACFLT at Pearl Harbor: • 2. Seize all available natural resources in Pacific • 3. Retire to defensive perimeter behind island barriers • 4. Await US to sue for peace • What warnings, if any, did the US have of Japan’s plans?* • Why was the US taken by both strategicandtactical surprise?*

15. Warnings & Indications • US had Intel on Japanese maneuverings early on: • SIGINT indications & MAGICdecrypted PURPLE(Japanese diplomatic message traffic) • So what was the problem? • “Connecting the ?_________:” • Unable to put all together in time at the operational & tactical level: • Also selective perception of US military leadership: • Prevailing attitude: Japanese military inferior to US • (With racist overtones of the period) • Warning to PacificFleet finally given • Via US mail! (Unable to send info by HF radio) • By that time it was too late – 0740 on Sunday morning

16. Dec 7, 1941: Air Raid Peal Harbor • Pacific Naval Balance: • Japanese Navy vs. Allies • Focus: Hawaiian Is (Ohau) • Pearl Harbor & Hickam Field • US Pacific Fleet: Battle ship row – NAS Ford Island • US Army & Army Air Corps: Hickam Field • Execution: 0740 & 0840 • 2 waves of Torpedo, bomber, & fighter aircraft strike USN & Air targets • Major targets: Navy’s BBs & CVs; and Aircraft at Hickam AirField • Japanese gain complete tactical surprise over unprepared US Army & Pacific Fleet

17. The Aftermath • Result of surprise attack: • USN Battleship Fleet sitting ducks at Ford Island • Sunk or heavily damaged • USA Air corps destroyed- most A/C parked wing tip to wing tip at Hickam • Tactical disaster & major operational set back for USN, but… • Political, strategic & $$$catastrophe for Japan • Adm Kimmel & Gen Short unjustly made scapegoats • Japan’s next major target was the PI

18. Philippine Invasion • Order of Battle: • Japanese Army: 14th Army with 2 Infantry Divisions & Fleet support • American & Philippine forces: • 30K US with 1 USMC Regiment • 35 B-17s & 100+ P-40s • 3 USN cruisers, 13 DDs, & 6 TBs, 29 SS • 10 PI Divisions (110K) • General Douglas MacArthur tried to defend too much: • Forward defense proved a critical tactical error as troops pulled back • Forced to abandon arty, ammo, rations • Major negative supply impact with time on retreating defenders

19. Bataan & Corregidor • Macarthur’s forward defense strategy on the beaches: • Plan Orange activated & Manila declared open city • Subsequent tactical impact – logistic shortfalls • Troops forced to abandon ammo/supplies during 2 week fighting withdrawal to Bataan Peninsula • Troops withdraw to defense phase lines on Bataan • Japanese Army amphibious invasion with reinforcements gradually overwhelm defenders • US strategic decision not to reinforce- why? • US Strategic priority? • Results: • Tactical & operational victory for Japan; • Strategic& operational set back for US; • Substantial casualties: 16K KIA with 84K taken POW • Many are killed during Batan death March • MacArthur ordered to escape via USN PB to Australia • To “return” another day – awarded MOH for evacuation ?______________ First!

20. Meanwhile… The Raid • Pressure on USG to respond to Pearl Harbordisaster mounts • FDR demands immediate results- Joint Chiefs under great pressure • Submarine (SS) Commander develops unique & highly risky plan • Order of Battle: • Halsey, Hornet, & Doolittle’s B-25 squadron versus: • Japan’s air defense & early warning system (to include trawlers)

21. Doolittle’s Raid (April 1942) • Concept of Operations: • USS Hornetto deploy 500 miles off Japan’s home islands • B-25sthen launch from USS Hornet & head for Tokyo • Then B-25s to conduct bomb run “30 seconds over Tokyo” • Target: Bomb key industrialinfrastructure • B-25s then continue on to China & land & recover w/aid of GWs

22. Execution, Results, & Significance • Friction: • Japanese trawlers spot Hornet Task Force 750 miles from Japan • Halsey forced to launch Doolittle earlier than desired – impact on B-25s? • Run out of ?__________ and forced to ?______________________ • Results: Tactical versus Operational & Strategic outcome: • Tactical: Raid does little physical damage to Japan’s industry • Strategic & political impact & significance? • Japanese military acutely embarrassed & US morale soars • Move up prep & attack for where?*

23. Battle of Midway- Lead-up (Spring 1942) • Japan established defensive perimeter IAW their strategy: • Employs Japanese Fleet in active defense • Then plans for two major operations: • New Guinea (against Australian forces) • Midway Island (1300 miles NW of Hawaii) • Operational Purpose: • Extend Japan’s defensive perimeter further East • Invade & capture Port Moresby (New Guinea) • Friction & problems: • Magic decrypts alert US of Japanese plans • Admiral Nimitz prepares USN & USMC to meet attack • Reinforces Midway Base with troops & aircraft • Deploys RADM Fletcher w/2 Carriers (CVs) to meet imminent threat off the Solomon Islands*

24. Battle of Coral Sea – (4-8 May, 1942) • USS Lexington & Yorktown deploy to SW Pacific: • Off Eastern tip of New Guinea • CV aircraft engage – totally out of sight of all ships involved • Battle damage: • Japan: Shohosunk, Shokaku damaged, A/C & crews destroyed • US: USS Lexingtonheavily damaged- later sunk by USN DD • Yorktown damaged => repairable (48 hours emergency repairs at Pearl) • Operational Results: • Prevents attack on Port Moresby • Japan’s expansion interrupted • 2 large CVs unavailable for Midway

25. Battle of Midway (June 1942)- The Plan • Japan’s Plan very complex: • Involved diversion of US Fleet toward North Pacific • Air assault & amphibious invasion of Midway island • Japanese Diversion plan: • 2 Lt CVs to attack US garrisons at Attu & Kiska • 4 BB screen real intent to south • SS advance force provide screen & early warning to East • Invasion plan: • Main CV air strike on Midway • Yamamoto then lies in ambush when US Fleet intervenes • 3rd Fleet to protect invasion force from SW of Midway

26. Friction & US Preparations • Magic – USN Intelhad brokenNavy Op code (JN-25): • Nimitz knows attack imminent (but not sure where) • How able to determine where Japan would strike? • N2 has series of “housekeeping” messages (complaints) sent • N2 ruse: broken ?_______ ________ plant reported at Midway • Transmitted in the clear • Japanese Intel encrypts & reports same info to Japanese HQ • Reveals their code for Midway by linking it with broken distillery at “AF” • USN response & Nimitz’s preparations: • Nimitz prep: re-enforces Midway w/Air & Land forces • Deploys Yorktown, Hornet, Enterprise to intercept Japanese • Rendezvous 350 miles NW of Midway at Point Luck • USN CV Target: Japan’s main CV force

27. Battle of Midway (4 June 1942)- Execution • TF-16 (Spruance) & TF-17 (Fletcher) combine & preposition to NE of Midway • Ahead of advance SS patrol • US virtually ignores diversionary attack on Aleutians • TF-17 launches recon A/C in search of Japanese CVs • ADM Nagumo launches 72 bombers with 35 fighter (Zero) escorts against Midway • 07:10 Midway torpedo & Marauder bombers attack Nagumo’s ships • Keeps second strike on stand by in anticipation of US Naval attack

28. Battle of Midway (4 June 1942)- Friction • Friction: bad luck hinder Japanese from onset: • Timing favors US • Japanese Bombers rigged with fragmentation bombs in prep for second strike on Midway • Japanese search aircraft spot ships of US Task Forces about same time US A/C spot Japanese CVs: • TF-17 (Fletcher) directs TF-16 (Spruance) to attack while Fletcher recovers his recon aircraft • Nagumo orders change out to armor piecing bombs to deal with US ships • Flight crews don’t have time to secure frag bombs from flight deck • Sacrifice of Devastators brings Japanese CV CAP Zeros to deck • Low & out of position as LCDR McClusky’s dive bombers arrive overhead & commence attack

29. Battle of Midway- “Scratch 3 flattops” • Timing of McClusky’s dive bombers catches Nagumo’s CVs at most vulnerable, with CAP on the “deck” • McClusky’sDauntless SBD-3s dive from 20K’ “like a silver waterfall” • Sink all three CVs: Akagi, Kaga, Soryu • US loses Yorktown by Hiryu • (which is later sunk) • Unique tactics employed? • All surface engagement during Battle conducted how? • Completely by CV aircraft- no ships directly engaged • Implication for future of BBs? • ?___________________ • Spruance suspends night ops & decides not to engage further (criticized later)

30. Operational Results & Strategic Significance • Battle of Midway impact & significance? • Two key questions: • Operational & tactical success? (why & for whom?) • Battle of Midway strategic impact & significance? • Operational & tactical success: • 1. CV air sunk 4 Japanese CVs (Type of success: ?__________ ) • 2. Threat to Midway eliminated (?_______________ success) • 3. Destroyed most of Japanese experience & veteran air crews (Tactical with operational implications?) • Impact on trained experienced crews?______ _______________ • Strategic impact: • Initiative in Pacific shifts to ?___________ & never shifts back • Plans for a counter-offensive soon generate competition for scarce Pacific resources

31. US Counter-offensive in Pacific • Nimitz & MacArthur: • Conflicting agenda of two Theatre CINCs (Central & SW Pacific) • Competition for scarce resources: • Army vs. Navy dispute results in JCS imposed compromise • “Complementary” Dual Strategiesquestioned by Allies (esp. British) • MacArthur’s proposed Operation against Rabaul (NE New Britain) • JCSagain imposes plan modification • 3 phased Operational approach: • 1. Capture Guadalcanal & Tulagi • 2. Advance along NE Coast of New Guinea • 3. Assault Rabual if practical

32. Battle of Salvo Island • Poor beginning: (Map) • USN lack of coordination in offload of USMC & equipment • Fletcher’s haste to depart w/CVs results in Abandonment of USMC on Guadalcanal • Marines left w/o adequate Naval protection • Japanese Navy strikes through “slot” near Salvo Island & attacks USN • Complete surprise & humiliating defeat for USN

33. War in the Atlantic • First Battles at Sea: Germany vs. Britainin surface action: • No contest => back to drawing board for Germany • Navy retreats to safety of German ports • Adjusted Strategy: U-Boats & surface ships as raiders; • Adm Donitz’s centralized C3 • Impressive early wolf pack success (“The happy times”) • Effective tactics & SS Wolfpack employment: • Tactics: spot=> signal to HQ=> converge & attack allied ships

34. Allied Response • Convoy system protection had mixed results • US learned the hard way about convoys • Finally adopted after serious losses to Subs • Still Allies suffered losses but also inflicts them • Allies finally able to effectively counter German SS threat- using Ultra & HF/DF: • Ultra identified SS convergence points • Allies turned Donitz C3 system to their advantage tracking HF transmissions (DF) • Now able to intercept Wolf Pack & attack • Brits attack from the air if Sub caught on the surface • Finally: US was able to produce more Liberty ships per month than SS could sink

35. The Air War- Strategic Bombing • RAF Bomber Command => Strategy & Target priorities: • Role of AM Harris & his strategic focus: • Target high concentration of civilian population (area bombing) • Day vs. Night time operations • Analysis results: precision bombing too hard • Hard enough to even hit cities at night (let alone point targets) • USAAF Op Strategy: US vs. British target priorities • Precision Bombing (day) vs. Area Bombing (night) • Target selection (divisive among allies) • US target focus:German aircraft industry => ball bearings • USStrategic objective: key economic nodes • Casablanca Meeting => compromise (of sorts) achieved: • AM Harris: insisted on area bombing (cities) • USAAF:precision day strikes on German industry • (But no truly common approach agreed to) • Reality: Allied strategy based primarily on tactical capabilities • If the Allies were to advance beyond Strategic Bombing- what was required first?

36. Mobilization & Power Projection • US mobilization presented several challenges: • 1st & foremost: recruit, equip, train, deploy, &employ manpower • 2nd : transform economic & industrial might into war economy • Great Britain’s mobilization involved greater sacrifices: • All Britishcitizens & industry fully dedicated to the war effort: • Serving in uniform, Home guard, or enduring Blackouts and the Blitz, • Waiting in Long lines for scarce goods, rationing, and paying high taxes • Germany’s mobilization was seriously flawed: • Hitler had delayed consolidation of early gains=> war economy • Slow to fully mobilize & also opposed to women in work force • Slave labor inefficient at best & vulnerable to sabotage at worse • Inadequate $$$ & industrial base & shortage of raw materials • Allied strategic bombing also caused inefficient decentralization

37. Assessment • US entered WWII because of a major strategic miscalculation: • Japan: surprise attack on Pearl Harbor aroused sleeping giant • Then Hitler: declared war on US • (Played into FDR’s political & military plans-Germany first strategy) • After all said & done => victory depended on what? • Successful ?__________ of allied industrial & economic power • +Translation of vast industrial potential into military power • And then ... => • Transport and project allied power into where needed • Time and U-boat threat: major challenge to this objective

38. Assessment- 2 • Britain and US must there4 tame Submarine threatfirst: • Brit/US must rely 1st on strategic air power projection into Germany • Only power projection tool available initially –why? • 1. Germany controlled ?_____- no foothold available to launch operations • 2. Allies not ready to invade Europe yet • But allies had to do something against Germany • How well did Allied strategic bombing do? • Allied strategic bombing ?______ as Operational objective • (Although gradually did pose threat to Nazi war $$$) • At too high cost in men, time, and A/Cfor limited benefit gained • Allies major accomplishment? • Total ?______________ of all its resources => • Mobilized on grand scale in a very short time frame • Key element to war’s final outcome – over time

39. Back-up Slides

40. RAF Bomber Campaign • Bomber Campaign at height (1943-44): • British workhorse: Lancaster Bomber • Operational focus: Ruhr River Valley • Key target: Ruhr Dams (high casualties) • Major RAF Bomber targets included: • Hamburg Firestorm (30-40K killed) • Peenemunde R & D station • Berlin (result in very high casualties) • Technological improvements helped reduce German radar interceptions: • “Windows” (?) • Bails of aluminum strips reflect radar • NTL- effective air defense tactics of Gen Kammhuber result in high casualties • Bottom line: • British campaign too costly => suspended

41. American Raids on Germany • US precision daylightTargets: • USAAF 8th AF workhorse during war: B-17 • P-40 & P-51 Fighter escort • Operational & tactical focus: • Ruhr, Regensbury, Schwenfurt • Aug-Oct’43:unescorted deep daylight raids into Germany • US suffered high casualties => • Result: 8th Air Force called off deep penetration raids • Target reality: Ball bearingsheld in large backlog • Easily obtained from neutral nations (Swiss & Swedes) • Also substitute easily made rollers

42. Luftwafffe • Goering’s role: could make Hitler laugh (& the Army cry) • Luftwaffe lacked effective leadership • Two major mistakes by Hitler & OKW regarding Luftwafffe? • 1. Diverted JU-52s to transport Troops in Tunisia: • (Shut down bomber pilot training!) • (Eating your young- future aircrew replacements?) • 2. Eastern Front – Stalingrad: • 6th Army denied permission to withdraw – why? Goering’s role? • Convinces Hitler Luftwaffe can re-supply 6th Army @ 600 tons/day • Dooms 6th Army as a result • Luftwaffe did provide heroic CAS to 6th Army • But with time => heavy losses mount up • After Sept ’43: Hitler shifts bulk of air power to West: • By then-Allies controlled all airspace over Eastern Front

43. The Air War- Strategic Bombing • RAF Bomber Command => Target priorities: • Role of AM Harris & his strategic focus: • Target high concentration of civilian population (area bombing) • Day vs. Night time operations • Analysis results: precision bombing too hard • Hard enough to even hit cities at night • Luftwafffe priorities: • Gain Air superiority trumps strategic Air Defense • Against RAF Bombers • Kammhuber’s role limited defense system • Night fighters effective in attacking RAF Bombers • Germany’s overall lack of support for air defense • Focused on offensive strikes

44. USAAF Operational Strategy • Contrasted priorities: American vs. Brit targets • Precision Bombing (day) vs. Area Bombing (night) • Target selection (divisive among allies – why?) • US:German aircraft industry => ball bearings • USStrategic objective: key economic nodes • Casablanca Meeting => compromise achieved: • AM Harris: insists on area bombing (cities) • USAAF:precision day strikes on German industry • (But no common approach agreed to) • Allied strategy based extensively on tactical capabilities

45. Mobilization & Power Projection • US challenges to mobilize- summarized as follows: • Recruit, equip, train, deploy, & employ manpower • Harness economic & industrial might to war economy • Great Britain’s mobilization involved greater sacrifices: • By 1944 24% of its labor were dedicated to the war • Civilian Defense Industry dedicated almost 18% of its capacity • All British citizens fully involved in war effort: • Blackouts, Blitz, Quarters shared with troops, Home guard duties • Long lines, scarce goods, Rationing, high taxes • Major problem: Brit antiquated Industrial infrastructure: • Motor industry => poor vehicle & tank performance • Especially telling during North Africa campaign

46. Mobilization- Germany • Inadequate economic & industrial base • Shortage of raw materials • Delay in consolidation gains => war economy: • Slow to enact full mobilization • Hitler’s ideological problem with women workers • Hitler’s hang-up prevents half population from helping • Slave labor inefficient & definitely unmotivated: • Sometimes even sabotage production • Impact of Allied strategic bombing: • Decentralization of production => very inefficient • Less produced with more time required to do it

47. Enigma & Ultra • British capture of U-Boat & its Enigma • Impact: Brits able to read enemy’s plans • (Photo: Guderian HQ w/Enigma machine) • Bletchley Park’srole • Advantage afforded to Allies by decrypted operational directives • Decrypted product called:Ultra • Allies finally able to counter German SS threat- also through HF/DF: • Frequent US-Brit cooperation & intelligence breakthroughs • Ultra identifies SS convergence points • Allies turn Donitz C3 to their advantage • Now able to intercept Wolf Pack & attack • Finally: US able to produce more Liberty ships than SS could sink