To overcome the immense distances of the Pacific Ocean and Japanese island occupation strategy intended to threaten the United States to sue for peace, the U.S. Navy devised a strategy called island hopping. It called for the armed forces to take successively closer island strongholds to[Clarification needed]
the Japanese mainland while leaving some in place[Clarification needed] to starve. From May 27 to June 20, 1944, the U.S. Army and Navy decisively eliminated the Japanese Army and Navy forces immediately northwest of New Guinea in the Battle of Biak after a long bloody campaign. The Japanese there maintained an airfield that could be improved by the Americans to use in the air war; also, Japanese presence there was perceived as a potential threat to the Australian mainland. The U.S. victory in the Battle of Saipan from June 15 to July 9, 1944 made Tinian, 5.6 kilometres (3.5 mi) south of Saipan, the next logical step in the Marianas campaign which would lead to retaking the Philippines and ultimately the defeat of Japan.
The 2nd and 4th Marine Divisions landed on 24 July 1944, supported by naval bombardment and artillery firing across the strait from Saipan. A successful feint for the major settlement of Tinian Town diverted defenders from the actual landing site on the north of the island. The battleship USS Colorado and the destroyer USS Norman Scott were both hit by six inch Japanese shore batteries. The Colorado was hit 22 times, killing 44 men. The Norman Scott was hit six times, killing the captain, Seymore Owens, and 22 of his seamen. The Japanese adopted the same stubborn resistance as on Saipan, retreating during the day and attacking at night. The gentler terrain of Tinian allowed the attackers more effective use of tanks and artillery than in the mountains of Saipan, and the island was secured in nine days of fighting. On July 31, the surviving Japanese launched a suicide charge.
The battle saw the first use of napalm in the Pacific. Of the 120 jettisonable tanks dropped during the operation, 25 contained the napalm mixture and the remainder an oil-gasoline mixture. Of the entire number, only 14 were duds, and eight of these were set afire by subsequent strafing runs. Carried by F4U Corsairs, the "fire bombs", also known as napalm bombs, burned away foliage concealing enemy installations.
Japanese losses were far greater than American losses. The Japanese lost 8,010. Only 313 Japanese were taken prisoner. American losses stood at 328 dead and 1,571 wounded. Several hundred Japanese troops held out in the jungles for months. The garrison on Aguijan Island off the southwest cape of Tinian, commanded by Lieutenant Kinichi Yamada, held out until the end of the war, surrendering on 4 September 1945. The last holdout on Tinian, Murata Susumu, was not captured until 1953.
After the battle, Tinian became an important base for further Allied operations in the Pacific Campaign. Camps were built for 50,000 troops. Fifteen thousand Seabees turned the island into the busiest airfield of the war, with six 2,400 m runways for attacks by B-29 Superfortress bombers on targets in the Philippines, the Ryukyu Islands and mainland Japan, including the atomic bombings of Hiroshima and Nagasaki.