Japanese air attacks on the Mariana Islands 27 in preparation for operations against Japan itself. The USAAF bases in the Mariana Islands were within range of a number of Japanese air bases in the Pacific. These included Wake Island to the east, Truk and the Gilbert and Marshall Islands to the southeast, Woleai to the south and Yap to the southwest. To the north the Japanese had air bases in the Nampo Shoto chain of islands and Bonin Islands, which included three airstrips on Iwo Jima. Several of the minor islands in the Mariana chain also remained in Japanese hands, and there were airfields on Rota and
Japanese air attacks on the Mariana Islands the Mariana and Palau Islands campaign. These islands were needed to provide bases for USAAF Twentieth Air Force B-29 Superfortress heavy bombers to attack the Japanese home islands. Construction of the large air bases needed to support B-29s began on Saipan in June 1944, before the end of the Battle of Saipan, and work on air fields on Tinian and Guam commenced in July and August respectively. The B-29s of the XXI Bomber Command began to arrive at Saipan starting on October 12, and the 73rd Bombardment Wing began flying warm-up missions against Japanese-held islands in the Pacific on October