D-Day in the Pacific: The Battle of Saipan

7. The Great Marianas Turkey Shoot

c h a p t e r s e v e n the great marianas turkey shoot Admiral Yamamoto Isoroku, commander in chief of the Imperial Japanese Navy at the start of World War II, had always promoted the idea of engaging the Americans in one large and decisive battle. The implementation of this plan had failed with Japan’s defeat at Midway in 1942. Nevertheless, Japanese naval commanders still hoped that a major confrontation with the American navy would turn the tide in their favor. Realizing that the American fleet was now larger than the Japanese navy and that the Americans had more carrier planes available, the Imperial Staff developed a plan to counter this growing inequity. In addition to the planes operating off of Japanese aircraft carriers, the Imperial Navy counted on its land-based planes spread throughout the Pacific on Japan’s island possessions. The islands, so-called unsinkable carriers, would provide the extra aircraft needed to defeat the United States by neutralizing its numerical superiority. The plan seemed to make strategic sense. The Japanese navy was still large and formidable. The number of planes available for flying off carriers , added to the number of land-based craft, gave Japan the theoretical possibility of negating the American advantage. Because Japan viewed Saipan as a crucial defensive outpost, the American invasion triggered the Japanese navy’s Operation A-Go, the plan for a showdown with the American Fifth Fleet. The Imperial Staff could not allow the landing on Saipan, within Japan’s inner defense zone, to go unchallenged. Imperial Headquarters Directive no. 373 ordered the navy and army to prepare the great marianas turkey shoot 91 “for decisive action” by the end of May.1 Further, with the American fleet exposed off the Marianas, the Japanese navy was prepared to engage in that large-scale battle that was intended to stop the American offensive. From Japan’s perspective, everything was in place. While success depended on the land-based aircraft, Japanese admirals did not realize that Mitscher’s Task Force 58, by hitting Truk, then the Marianas, then the Palaus, and then Saipan again, had already destroyed many of the planes that were essential to Operation A-Go. Japanese naval commanders typically underestimated and underreported their losses after encounters with American forces, and they had replicated this problem on Guam, Truk, and Saipan as well as other locations in the Pacific. Further, due to Japan’s significant losses in 1943 and the first half of 1944, few experienced pilots were available to replace the high-quality flyers who had participated and who had been lost in missions at the beginning of the war. Japanese pilots now had less battle experience than their American counterparts. When Japan launched Operation AGo , naval commanders thought that they had more planes available than was the case in reality. Nevertheless, Japanese military leaders, unaware of these problems and other flaws in their plans, joined the confrontation enthusiastically. Admiral Yamamoto was killed in 1943, and his successor as commander in chief of the Imperial Navy was Admiral Koga Mineichi. Like Admiral King, Koga understood the importance of the Marianas to the Japanese war effort. According to the U.S. Strategic Bombing Survey, Koga “announced his decision to hold the Marianas-Palau line until death, feeling that once this inner defense line was broken there could be no further hope for Japan.”2 At the end of March 1944 Koga was killed when his plane disappeared in bad weather. His replacement was Admiral Toyoda Soemu, a graduate of Japan’s Imperial Naval Academy. Promoted to admiral in 1941, Toyoda served as a member of the Supreme War Council from May 1943 and then became commander in chief of the navy in May 1944.3 He assumed his new position at a crucial moment in the war, with the Americans pushing relentlessly across New Guinea toward the Philippines and northwest across the central Pacific toward Japan’s essential defense line in the Marianas. Japan had to stop the United States, and a decisive naval battle seemed to offer some hope of success. The Imperial Staff could not allow the attack on Saipan to go unchallenged, and they issued the order to implement Operation A-Go, unaware of the extent of Japan’s air losses. By destroying hundreds of Japanese land-based planes during the first 92 d-day in the pacific half of 1944...