Sea Power and Maritime Affairs: Sea Power and Maritime Affairs The War in the Pacific Offensive Phase


Slide3: “We shall never forget that it was our submarines that held the lines against the enemy while our fleets replaced losses and repaired wounds.” - Fleet Admiral Chester Nimitz, 1947


Unrestricted Submarine Warfare: Unrestricted Submarine Warfare Commences immediately following Pearl Harbor attack by order of CNO 24 war patrols in Dec 1941 (Sink 19 ships) Early emphasis on capital ships (Limited success) Early Problems: Extremely cautious commanders and tactics led to disappointing results early in the war Torpedo Problems: Early detonation of magnetic exploder (Too sensitive) Disabled to rely on contact exploder Firing Pin problems Steam propulsion eventually replaced by electric Once problems solved, the US finally had a reliable torpedo Late 1943: Radar installed; sonar improved


Subs in the Pacific: Operations: Subs in the Pacific: Operations Reconnaissance and landing commandoes Covert supply and evacuation of key personnel Includes Filipino President and Cryptanalysts Lifeguard Duty: 504 airmen rescued Sank 5,320,094 Tons of shipping during the war Overall account for more than 50% of enemy losses at sea More than 1300 Japanese ships June 1945, 9 US subs move into Sea of Japan Sink 28 vessels in 20 days USS Barb lands shore party in Japan, plants explosives on railway and blows up train Especially dangerous: 22% never returned 1 sub/67 sailors lost for every 27 ships sunk


Japanese Merchant Shipping: Japanese Merchant Shipping


US Pacific Strategy: Dual Advance: US Pacific Strategy: Dual Advance MacArthur: Army supported by land-based airplanes with older battleships/cruisers “leapfrog” across northern coast of New Guinea to the Philippines Leaps measured by range of bombers Larger land mass allows maneuver Nimitz: Carriers support USMC and Army forces to “island-hop” across the central Pacific Plan Orange Small islands necessitate frontal assaults “Opportunistic” Hit where advantageous Once captured land-based planes free up carriers


Slide8: US Pacific Strategy Both plans use control of the sea and air to maneuver, bypassing and isolating Japanese strongholds


Dual Advance: South Pacific: Dual Advance: South Pacific Mission: Drive up the New Guinea-Mindanao Axis from the south, towards Philippines and Japan Contain Japanese in south to prevent them opposing drive across the Central Pacific McArthur wanted this to be the main drive Plan: Mainly Army offensive with amphibious assaults on lightly defended enemy islands, supported by naval bombardments, convoy and transport Continuous air support by aircraft operating from airfields on newly captured islands


Dual Advance: Central Pacific: Dual Advance: Central Pacific Mission: Drive through islands of central Pacific, capturing them as forward bases Cut Japan’s SLOCs to mainland & SW Pacific. Central Pacific would be the main line of advance Plan: Push accomplished by carrier air cover and Marine amphibious divisions Able to bypass some strongholds and attack at will. Major campaigns in the Gilberts, the Marshalls, and the Marianas


Army - Navy Compromise: Army - Navy Compromise MacArthur proposes retaking Rabaul Admiral King (CNO) objects to MacArthur’s plan Proposes step-by-step advance through Solomons to re-take Rabaul Nimitz in command with USMC making amphibious assaults and Navy providing support Army forces used as garrisons for islands Compromise: Initial advance in Eastern Solomons under Nimitz Boundary between SWPA and POA moved west MacArthur takes command after Tulagi secured


Prelude to Guadalcanal: Prelude to Guadalcanal Japanese shocked by defeat at Midway Cancel plans to take Fiji, Samoa, and New Caledonia Must proceed with plan to take Port Moresby Within bomber range of stronghold at Rabaul Japanese begin building airfield at Guadalcanal European cross-channel invasion not possible in 1942 CNO transfers landing craft to the Pacific Nimitz moves to reinforce South Pacific Area Protect vital sea lines of communication with Australia Two bases established in New Hebrides


Guadalcanal Campaign (Aug 1942-Feb 1943): Guadalcanal Campaign (Aug 1942-Feb 1943) Operation WATCHTOWER MacArthur: More forces needed Invasion of North Africa – Drain on amphibious forces Guadalcanal substituted for Santa Cruz Islands after U.S. learns of Japanese building airfield Amphibious landing virtually unopposed Marines take Henderson Field Both sides pour in resources for 6 months Japan dominates nighttime action More emphasis during pre-war training “Tokyo Express” down “The Slot” into “Ironbottom Sound” US dominates daytime with shore and carrier aircraft Japanese withdraw Feb 1943


Slide14: “Tokyo Express”


Guadalcanal CampaignAugust 1942 – February 1943: Guadalcanal Campaign August 1942 – February 1943 Series of naval battles while Marines hold Henderson Field Battle of Savo Island (09 August): Allies defeated in night surface action With exception of Pearl Harbor worst defeat in US naval history Battle of the Eastern Solomons (24-25 August): Carrier battle Japanese carrier Ryujo sunk, USS Enterprise damaged USS Wasp sunk and Saratoga damaged by Japanese submarines Battle of Cape Esperance (11-12 October): Night surface action Avenges Savo Island Battle of the Santa Cruz Islands (26-27 October): Yamamoto sends Nagumo to finish US carriers Hornet sunk, Enterprise damaged (No operational carriers left) Battle of Tassafaronga (29 November): Night surface action RADM Wright maintains course/speed allows targeting by Japanese torpedoes


Central Solomons Campaign: Central Solomons Campaign Operation CARTWHEEL (July – November 1943) MacArthur and Halsey conduct simultaneous assaults toward Rabaul from the south and east Yamamoto strips his carriers of aircraft to reinforce Rabaul Yamamoto killed by P-38 attack from Guadalcanal American intelligence learned of his travel plans Orders directly from the White House Advances in amphibious tactical doctrine over Guadalcanal US institutes “bypassing” strategy Avoid, isolate, and neutralize heavily defended islands Examples: Kolombangara/Rabaul/Truk US ships become more proficient in combat Radar use increases accuracy of naval fire Combat Information Centers established Improved night tactics


The Gilberts: Tarawa: The Gilberts: Tarawa American warship production allows Central Pacific drive 6 new Essex-class fleet carriers and 6 new Independence-class light carriers join the fleet in Aug/Sept 1943 Objective: Gain airfield on Betio Island to launch further attacks in Central Pacific Issues: Coral reefs disrupt landings Inadequate shore bombardment Costly battle: Three days cost US more than 3,000 Marine casualties Only 17 of 5,000 Japanese taken alive


The Marshalls: Kwajalein: The Marshalls: Kwajalein


The Marshalls: Kwajalein: The Marshalls: Kwajalein After the Tarawa, concern for death toll in Marshalls Japanese controlled since 1914 Ring of airbases, two on Kwajalein Tarawa lessons learned used to good advantage: Better naval gunfire support Longer preliminary bombing Specific targets vice lobbing on land Better command and control Intelligence gathering RADM Mitscher attacks with carriers Over 6,000 sorties destroys Japanese air power Neutralizes Truk Total Marshall loss less than first day of Tarawa


Drive Across the Pacific: The Marianas: Drive Across the Pacific: The Marianas 15-18 Jun 1944: U.S. “hops” more than 1,000 miles to invade the Marianas Requires huge fleet: More than 700 vessels to carry 127,000 men and all supplies Brings Japanese home islands within range of B-29’s Results of conquest : 5,000 U.S. deaths, 50,000+ Japanese deaths U.S. bases for further advances Sub base for attacks on Japanese shipping Beginning of the end for Japan Tojo government falls Attack on Marianas draws out the Japanese fleet and results in Battle of Philippine Sea


Battle of the Philippine Sea: Battle of the Philippine Sea 19-20 Jun 1944: US submarines had limited oil to Japanese fleet Limited operations to the Western Pacific Fleet tops off with unprocessed crude oil Albacore and Seahorse report location and composition of Japanese fleets approaching Japanese launch four raids on US carriers Expected help from land-based planes on Guam Inexperienced Japanese aviators lose 346 aircraft U.S. subs sink two Japanese carriers which were operating on highly volatile crude oil Japanese fleet retreats NW Japanese naval air power ceases exist “The Great Marianas Turkey Shoot”


Liberation of the Philippines: Liberation of the Philippines U.S. advance continues after Marianas Campaign MacArthur’s forces capture New Guinea Debate on whether to bypass Mindanao MacArthur - Must honor promises to the Filipino people Liberate all the Philippines as soon as possible King – Invade only Luzon and then Taiwan Nimitz does not cancel invasion of Peleliu Japanese allow landings – defend the interior of the island 10,000 Marine casualties – Nimitz highly criticized U.S. forces advance towards Philippines Japanese sortie entire fleet Attempt to maintain defenses and communications with Southern Resources Area


Philippines Invasion: Philippines Invasion Preliminaries: Air raids from carriers 12 Sep 44 Attack on Palau 15 Sep 44 Attack on Ulithi 24 Sep 44 Blockading with China-based bombers & Halsey’s carriers 17 Oct 44: Rangers go ashore 18-20 Oct 44: NGFS 20 Oct 44: Troops land on Leyte MacArthur goes ashore


Japanese Reaction: Loss of Philippines would divide Japanese holdings Japanese launch an elaborate naval defense plan of Philippines known as SHO-1 Center Force: (VADM Kurita) Surface force from Malaysia 5 battleships, 12 cruisers, 15 destroyers Southern Force: (VADMs Nishimura and Shima) Surface force from Malaysia supplemented from Japan 2 battleships, 4 cruisers, 8 destroyers Northern Force: (ADM Ozawa) Four carriers as decoys to lure Halsey away Key to Japanese strategy Japanese Reaction


Battle for Leyte Gulf: Battle for Leyte Gulf “In case opportunity for destruction of the major portion of the enemy fleet is offered or can be created, such destruction becomes the primary task.” - Standing Order of Admiral Nimitz


Battle for Leyte Gulf23-25 Oct 1944: Battle for Leyte Gulf 23-25 Oct 1944


Battle for Leyte Gulf: 23-24 Oct 44: Battle for Leyte Gulf: 23-24 Oct 44 U.S. submarines (Darter and Dace) spot Central Force in the South China Sea at 0600 on October 23rd They report the approaching force, warning Halsey and 3rd Fleet The subs then attack after the force sails by: Sink two cruisers (including Kurita’s flagship) Badly damage a third Admiral Kurita fished from the water by Kishinami Halsey launched five successive air attacks on the 24th Sink the monster battleship Musashi, damage three others No land-based air support form Philippines Planes attack US carriers with little success Kurita reverses course


Battle for Leyte Gulf: Battle for Leyte Gulf Late 24 Oct 1944 Halsey gets reports Kurita is retreating and announces formation of TF-34 (4 battleships, 6 cruisers, 14 destroyers) Doesn’t execute Kinkaid overheard messages and believes TF-34 is guarding outlet of San Bernardino Strait US search planes spot Ozawa’s carrier force around 5 p.m. and Halsey proceeds north to engage at dawn (with TF-34) VADM Kinkaid (7th Fleet) orders RADM Oldendorf to plug Surigao Strait with PT boats, destroyers, cruisers and 6 old battleships after aircraft spot Southern Japanese Force


Battle for Leyte Gulf: Surigao Strait: Battle for Leyte Gulf: Surigao Strait Night of 24/25 Oct 1944: Southern Force runs into Oldendorf’s trap in strait PT boats and destroyers harass force with torpedoes Sink a destroyer and hit both battleships (One blown in half) Oldendorf’s cruisers and battleships “cross the T” Only 1 destroyer from Nishimura’s force survives One-sided and complete naval victory San Bernardino Strait left unguarded due to miscommunication and confusion within chain of command allowing Central Force to slip through


Battle for Leyte Gulf: Surigao Strait24/25 Oct 1944: Battle for Leyte Gulf: Surigao Strait 24/25 Oct 1944


Battle for Leyte GulfOctober 25, 1944: Battle for Leyte Gulf October 25, 1944 “Where is, repeat, where is Task Force 34? The world wonders.” – Nimitz message to Halsey


Battle for Leyte Gulf: 25 Oct 1944: Battle for Leyte Gulf: 25 Oct 1944 Battle off Cape Engaño: Halsey destroys Ozawa’s Northern Force but not in position to assist TAFFY-3 Battle off Samar: Kurita’s Central Force encounters 7th Fleet’s outgunned TAFFY-3 escort carrier task unit TAFFY-3 runs to launch escort planes, attacks with airplanes, destroyers, and calls for help Central Force turns back Thought ships spotted were Halsey’s 3rd Fleet Did previous sinking impact Kurita?


Leyte Gulf Results: Leyte Gulf Results Japanese Fleet shattered Carriers decimated No more serious opposition to US in the Pacific Opened door for further landings in support of MacArthur’s campaign Philippines under US control by April 1945 Japanese begin resorting to kamikaze tactics Set the stage for advance on Japan Last great battleship engagement in history


Slide34: Japanese soil 650 miles from Tokyo Crucial to B-29 raids on mainland Japan Deny Japanese use for fighters/kamikaze’s Base for US fighter escorts Divert for crippled B-29’s Took over a month US: 19,000 wounded; 7,000 dead Japanese: 21,000 defenders, 216 taken alive Why Iwo Jima?


Okinawa: Okinawa Purpose: Complete blockade of Japan from south Airbase for bombings of Japanese mainland Initial landing: 01 Apr 1945, 183,000 troops Unopposed on the beach Gen Ushijima entrenched with 100,000 defenders Japanese needed a miracle Kamikaze (Divine Wind) attacks Over 2,000 assaults launched Sank 34 US ships Damaged 368 others Conquest lasted until 21 Jun 1945, costing 7,600 lives and 31,800 wounded Japanese lose more than 81,000 killed


Manhattan Project: Atomic Bomb: Manhattan Project: Atomic Bomb Successful test July 16, 1945 in New Mexico Potsdam Declaration: “Unconditional surrender” lest it face “prompt and utter destruction” Japanese reject on July 26th President Truman orders two bombings Hiroshima – 06 Aug 1945 Nagasaki – 09 Aug 1945 Believed potential for casualties during a struggle for the Japan is too high


Defeat of Japan: Defeat of Japan 09 Aug 45: – USSR declares war on Japan. – Red Army moves into Manchuria 10 Aug 45: – Japan accepts Potsdam Proclamation 15 Aug 45: – Cease Fire 2 Sep 45: – Japanese surrender on Missouri in Tokyo Bay


Geopolitical effects of WWII: Geopolitical effects of WWII Germany/Japan in ruins Accelerates national freedom movements (India, Indonesia, etc.) genesis of the “Third World” US and USSR rise to dominance Sets Cold War stage for future conflicts Berlin “blockade” Korea/Vietnam Beginning of the Nuclear Age Redrawn boundaries lead to future conflicts Arab/Israeli conflicts Yugoslavia


Slide40: Next time: The Navy and the Early Cold War