World War II: Pacific Theater Notes from 05-16-11

The Pacific Theater

Imperial Japan Japan saw the US and others as a threat to its influence in Asia and in 1940 the Japanese began developing plans to destroy the US Navy in Hawaii On Dec 7, 1941, the Japanese attacked Pearl Harbor In May 1940, the main part of the US fleet was transferred to Pearl Harbor from the west coast

Pearl Harbor Dec 7, 1941 Americans taken completely by surprise “a date which will live in infamy” Americans taken completely by surprise The first attack wave targeted airfields and battleships The second wave targeted other ships and shipyard facilities

Broader Results In spite of the tactical success, the attack on Pearl Harbor was an operational and strategic failure for the Japanese The attack failed to destroy the American aircraft carriers, fleet repair facilities, or fuel reserves The “sneak attack” galvanized American support for entry into the war

Fall of the Philippines Shortly after Pearl Harbor the Japanese made initial landings on Luzon, then made their main landings on Dec 22 On Dec 24, MacArthur ordered his forces to withdraw to the Bataan Peninsula By Apr Bataan surrendered By early May Corregidor surrendered Douglas MacArthur in his headquarters tunnel at Corregidor in March 1942

Bataan Death March President Roosevelt ordered MacArthur to relinquish command to Lieutenant General Jonathan Wainwright and MacArthur escaped to Australia 25,000 Americans and Filipinos died on the Bataan Death March to captivity

Coral Sea (May 4-8, 1942) US had been able to intercept Japanese radio traffic in an operation called “MAGIC” MAGIC intercepts allowed Admiral Nimitz to position two carriers off the eastern tip of New Guinea Both sides suffered heavy losses but the Japanese were forced to call off their amphibious attack on Port Moresby Battle waged exclusively via air strikes Opposing surface ships never made direct contact Admiral Chester Nimitz, Commander in Chief Pacific and Pacific Ocean Areas

Midway (June 3-6, 1942) Japanese planned a diversionary attack on the Aleutian Islands while the main force attacked Midway to destroy the American fleet Thanks to MAGIC intercepts, US didn’t fall for the Alaska feint and reinforced Midway Americans destroyed four Japanese carriers and most of their flight crews Japanese advance was checked and initiative in the Pacific began to turn to the Americans

Greatest Extent of Greater East Asia Co-prosperity Sphere

Twin Drives Chief of Naval Operations Admiral Ernest King favored a drive across the central Pacific moving toward Japan over the coral atolls scattered across the Pacific Take advantage of ability to leap across vast distances MacArthur favored an advance across the South Pacific via New Guinea and the Philippines Meet obligations to Filipinos Maintain pressure against the retreating Japanese Protect against a renewed threat against Australia Admiral Ernest King

Compromise King’s planned drive would move first against the Gilbert Islands and then toward the Philippines MacArthur would likewise advance toward the Philippines Joint Chiefs gave no clear priority to either drive “Mutual supporting” or “mutually competing?” Chester Nimitz, Commander in Chief Pacific and Pacific Ocean Areas and William Halsey, Commander, South Pacific Area and South Pacific Force

Operation Cartwheel Became the model for Pacific commanders throughout the rest of the war don’t move island to island; advance by great bounds using air superiority bypass major strongpoints and leave them reduced to strategic and tactical impotence hit Japanese weak spots; avoid frontal assaults; use deception and surprise seize existing airfields and ports and use these newly acquired bases to support the next leap forward

Retaking the Philippines The invasion of the Philippines brought MacArthur and Nimitz’s twin drives together On Oct 20, 1944, MacArthur attacked Leyte

Battle of Leyte Gulf The American and Japanese surface fleets made contact the night of October 24-25 in the San Bernardino Strait Two Japanese task forces entered the strait, Halsey did the classic naval maneuver of crossing the “T” and sank all but one enemy destroyer

Escort carrier St. Lo sunk by kamikaze attack Battle of Leyte Gulf However, Halsey was surprised shortly after dawn when Japanese heavy cruisers and battleships passed unopposed through the San Bernardino Straits and threatened the invasion fleet American aircraft turned back the already weakened Japanese Still the Japanese did not give up, delivering their first wave of kamikaze attacks Escort carrier St. Lo sunk by kamikaze attack

“I shall return”

Raising the flag on Mt. Suribachi, Iwo Jima Final Campaigns From Feb 19 to Mar 11, 1945 the Marines captured Iwo Jima From Apr to June Americans captured Okinawa Total American battle casualties were 49,151, of which 12,520 were killed or missing and 36,631 wounded Approximately 110,000 Japanese were killed and 7,400 more were taken prisoners Okinawa showed how costly an invasion of the Japanese home islands would be Raising the flag on Mt. Suribachi, Iwo Jima

Operation Cornet, the plan to take Tokyo Plan to Invade Japan US planned to invade Japan with eleven Army and Marine divisions (650,000 troops) Casualty estimates for the operation were as high as 1,400,000 Truman decided to use the atomic bomb to avoid such losses Operation Cornet, the plan to take Tokyo

The Atomic Bomb In the early 1940s, America had started an atomic weapons development program code named the “Manhattan Project” A successful test was conducted at Alamogordo in New Mexico in July 1945 J. Robert Oppenheimer and General Leslie Groves at the Trinity Site soon after the test

Hiroshima and Nagasaki Hiroshima Aug 6, 1945 90,000 killed On Aug 8, the USSR declared war on Japan and invaded Manchuria the next day Nagasaki Aug 9, 1945 35,000 killed Okinawa had been much more costly than Hiroshima and Nagasaki Captain Paul Tibbets piloted the plane that dropped the bomb on Hiroshima

Hiroshima, vicinity of ground zero

Japan surrenders Sept 2, 1945 aboard the USS Missouri