Japanese air attacks on the Mariana Islands and anti-aircraft guns shot down about 37 Japanese aircraft during these raids. After the Marianas began to come under attack, the United States military stepped up its raids on the Japanese-held islands which could be used to launch raids on the B-29 bases. Particular attention was given to Iwo Jima, as it was correctly assumed that the Japanese aircraft which attacked the Marianas were flying from Japan and staging through the island en route to their targets. Following the first raid against Saipan in November, XXI Bomber Command B-29s were dispatched against Iwo Jima's airfields on November 5 and 8.
Imperial Japanese Navy in World War II on the American perimeter. The Japanese continued to underestimate the number of American forces on the island, assuming that were that only 2,000 marines were on the island. However, the actual number was closer to 20,000, subsequently attacks launched by the Japanese on two successive nights on September 12–14, failed. Meanwhile, the Japanese did better in the struggle for control of the waters around Guadalcanal. On September 15, the submarine sank the carrier , leaving only a single American carrier, the , active in the Pacific at the time. However, as the Japanese possessed up to six operational carriers during