Mariana and Palau Islands campaign

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Mariana and Palau Islands campaign
Part of the Pacific Theater of World War II
A U.S. LVT loaded with Marines approaches Tinian during the U.S. landings on that island.
Date June – November 1944 Location Mariana and Palau Islands, Pacific Ocean Result American victory
Belligerents
United States	Japan
Commanders and leaders
Chester W. Nimitz Raymond A. Spruance Richmond K. Turner Holland Smith Roy Geiger Harry Schmidt William H. Rupertus Paul J. Mueller	Yoshitsugu Saito † Chuichi Nagumo † Jisaburō Ozawa Kakuji Kakuta † Takeshi Takashina † Hideyoshi Obata † Kiyochi Ogata † Sadae Inoue Kunio Nakagawa †
Strength
128,000 600+ ships	71,000
Casualties and losses
8,125 killed and missing	67,000+ killed

Granite II (Mariana and Palau Islands campaign)

1100km
684miles

Palaus

Marianas

Philippine
   Sea

Philippines

Luzon

Leyte

Formosa

Angaur

Peleliu

Guam

Tinian

Saipan

   

  Operation Forager

  Operation Stalemate

  Operation Causeway (cancelled)

The Mariana and Palau Islands campaign, also known as Campaign Plan Granite II, was an offensive launched by the United States against Imperial Japanese forces in the Pacific between June and November 1944 during the Pacific War.^[1] The campaign consisted of Operation Forager, which captured the Mariana Islands, and Operation Stalemate, which captured Palau. Operation Causeway, an invasion of Japanese-controlled Taiwan, was also planned but not executed.^[2] The offensive, under the overall command of Chester W. Nimitz, followed the Gilbert and Marshall Islands campaign and was intended to neutralize Japanese bases in the central Pacific, support the Allied drive to retake the Philippines, and provide bases for a strategic bombing campaign against Japan.

The United States assembled a significant combined arms task force to undertaken the campaign. The Fifth Fleet was commanded by Admiral Raymond A. Spruance. Task Force 58, commanded by Vice Admiral Marc Mitscher, consisted of 15 carriers, 7 battleships, 11 cruisers, 86 destroyers and over 900 planes. The amphibious invasion force, commanded by Vice Admiral Richmond K. Turner, consisted of 56 attack transports, 84 landing craft and over 127,000 troops.^[3]

At the beginning of the campaign, United States Marine Corps and United States Army forces, with support from the United States Navy, executed landings on Saipan in June 1944. In response, the Imperial Japanese Navy's Combined Fleet sortied to attack the U.S. Navy force supporting the landings. In the resulting Battle of the Philippine Sea (also known as the "Great Marianas Turkey Shoot") on 19–20 June, the Japanese naval forces were decisively defeated with heavy and irreplaceable losses to their carrier-borne and land-based aircraft.

U.S. forces landed on Saipan in June 1944 and on Guam and Tinian in July 1944. After heavy fighting, Saipan was secured in July and Guam and Tinian in August 1944. The U.S. then constructed airfields on Saipan and Tinian from which B-29s were able to conduct strategic bombing missions against the Japanese home islands until the end of World War II, including the nuclear attacks on Hiroshima and Nagasaki.

In the meantime, in order to secure the flank for U.S. forces preparing to attack Japanese forces in the Philippines, U.S. Marine and Army forces landed on the islands of Peleliu and Angaur in Palau in September 1944. After heavy fighting, both islands were finally secured by U.S. forces in November 1944, while the main Japanese garrison in the Palaus on Koror was bypassed altogether, only to surrender in August 1945 with the Japan’s capitulation.

Following their landings in the Mariana and Palau Islands, Allied forces continued their ultimately successful campaign against Japan by landing in the Philippines in October 1944 and the Volcano and Ryukyu Islands beginning in January 1945.