Battle for Okinawa

Battle for Okinawa

The capture of Okinawa was the final preliminary to an invasion of the Japanese home islands. Located in the Ryukyu group of islands between Kyumshum, the southernmost island of Japan, and Taiwan (Formosa), Okinawa is about 60 miles long and at most 18 miles wide. Taken by Japan in 1875, Okinawa is mountainous in the north and south and level and cultivated in the central portion. If the United States could take the island, it would sever Japanese communications with southern China, but the principal reason was to secure a staging area for the projected invasion of Japan. Okinawa offered suitable air bases, anchorages, and staging grounds for such a vast undertaking.

The operation, code-named iceberg, fell to Admiral Raymond Spruance’s Fifth Fleet. The lifting force consisted of 1,213 vessels of 45 different classes and types in Vice Admiral Richmond Kelly Turner’s Task Force (TF) 51. The vessels ranged from 179 attack transports and cargo ships to 187 landing ship tanks. This does not include the covering force of 88 ships of Vice Admiral Marc Mitscher’s TF-58 or the 22 ships of TF-57, a British component commanded by Vice Admiral H. B. Rawlings.

The land assault force for what would be the Pacific theater’s largest and most complicated amphibious operation was U.S. Army lieutenant general Simon Bolivar Buckner’s Tenth Army of some 180,000 men. It consisted of Major General Roy S. Geiger’s III Marine Amphibious Corps (1st, 2nd, and 6th Marine divisions) and Major General John R. Hodge’s XXIV Army Corps (7th, 27th, 77th, and 96th Infantry divisions).

Tokyo had begun strengthening Okinawa at the end of March 1944 with the activation of the Thirty-second Army (Ryukus). By October 1944 it contained four divisions (9th, 24th, 62nd, and 28th divisions on Sakishima) plus other units. Altogether, Japanese commander on Okinawa Lieutenant General Ushijima Mitsuru commanded about 130,000 men, including the 20,000-man Okinawan Home Guard. The Japanese constructed a formidable defensive system, particularly on the southern part of the island.

In the second half of March 1945 U.S. forces sought to isolate Okinawa by striking Japanese air bases on Kyumshum and the Sakishima island group between Formosa and Okinawa. Army heavy bombers also hit Formosa and the Japanese home island of Honshu. During these operations the ships, especially the aircraft carriers, came under heavy Japanese kamikaze attacks. Named for the Divine Wind (Kamikaze), a 13th-century typhoon that saved Japan from invasion by Kublai Khan’s fleet, kamikazes were first utilized by the Japanese during the Battle of Leyte Gulf, when they sank the escort carrier St. Lô and badly damaged other ships.

During March 18–19, 1945, Allied ships off Okinawa came under a heavy kamikaze attack. The carrier Franklin took two bomb hits on its flight deck that nearly incinerated the upper decks. Heroic efforts by the crew saved the carrier, but the attacks led to the loss of 724 men, the highest casualty rate of any surviving U.S. Navy vessel in any war. The carrier Wasp was also hit by a kamikaze but was saved thanks only to new fire-fighting techniques.

During March 14–31 air attacks and naval shelling proceeded against Okinawa. Then beginning on March 23, the 77th Infantry Division secured the outlying Kerama Islands. This provided anchorages and artillery positions for the invasion force and led to the destruction of some 300 small Japanese suicide boats.On the morning of Easter Sunday, April 1, the Americans went ashore on Okinawa proper, landing on the west-coast Kadena beaches. Some 16,000 troops came ashore in the first hour, and 50,000 had come ashore by the end of the day.

Once again the initial assault was deceptively easy, as the Japanese did not contest the beaches but instead chose to fight in the more populous interior.The U.S. Marine Corps III Amphibious Corps on the left (1st and 6th divisions) now turned north. The corps met relatively little opposition in clearing the northern area by April 13 and nearby Ie Shima Island during April 16–20. The U.S. Army XXIV Corps swung south. The main landing was facilitated by a demonstration against the southern end of the island by the Marine Corps 2nd Division.

The 27th and 77th Infantry divisions were held in reserve. Ushijima now had the majority of his 24th and 62nd divisions in the rugged southern end of the island, where they could mount a determined defense.It was at this point, beginning on April 7, that the Japanese launched their first major kamikaze assault, aimed at driving the Allied fleet from Okinawa. Some 121 kamikazes and 117 additional orthodox aircraft swept in on the amphibious force. The Americans claimed 383 of the attackers shot down, but 2 U.S. destroyers and 4 smaller ships were sunk and 24 other vessels damaged.

The Allies countered by extending their destroyer screen to 95 miles from Okinawa. The destroyers provided early warning of the attacks but also became easy targets for the kamikazes. From April 6 until July 29 Japanese suicide attacks pounded the destroyer screen, and 14 destroyers were sunk. Through June 10 the Japanese had launched nearly a dozen mass kamikaze raids of between 50 and 300 planes each against the invasion fleet. During the two months that the U.S. Navy was off Okinawa, the navy underwent 2,482 kamikaze attacks. The kamikazes were eventually defeated by new defensive formations that provided maximum antiaircraft fire protection to the carriers and by crushing Allied air superiority.

The largest kamikaze was actually a battleship, the Yamato. Departing Japan on April 6 on a one-way mission to Okinawa to attack the invasion fleet and then be beached as a stationary fort, the giant battleship and its escort force of 1 cruiser and 8 destroyers were intercepted on April 7 by 180 U.S. carrier aircraft 200 miles from Okinawa and were sunk in a furious assault of nearly four hours. Only 269 officers and men were rescued; 3,063 aboard the Yamato died. U.S. planes also sank 1 light cruiser and 4 escorting destroyers, killing another 1,187 officers and men. U.S. losses in the attack came to 10 aircraft and 12 men.

Meanwhile in fighting on land, XXIV Corps met stiff resistance in the south. Japanese defenders were well dug in along a series of east-west ridge lines across the island, and they incorporated Okinawan burial caves in their successive, mutually supporting positions. The U.S. advance soon ground to a halt.On April 22 the 1st Marine Division took up position on the right of the line; it was joined there later by the 6th Marine Division. The marines then came up against the main Japanese defensive line, with the heart of its defense at Shuri Castle. On May 4 the Japanese mounted a desperate counterattack that made some headway before it was blunted.

On May 18 the marines took Sugar Loaf Hill, the western portion of the Shuri Line. Four days later the Japanese withdrew seven miles south to a new line.Final operations occurred in June, but on June 18 Buckner was killed by a Japanese shell while at a forward observation post, the highest-ranking U.S. officer lost to hostile fire in the war. Geiger then took command. He was the only U.S. marine ever to command a field army, and he directed the final days of fighting.

Although pockets of resistance remained, Geiger declared the island secure on June 21. The Americans took only 7,400 Japanese prisoners. General Ushijima committed ritual suicide. The Japanese suffered 92,000–94,000 military dead. The Battle for Okinawa was a bloodbath for both sides, the costliest battle for the Americans in the Pacific theater. The U.S. Army lost 12,520 dead and 36,631 wounded. The marines suffered 2,938 dead and 13,708 wounded. The navy lost 4,907 men killed and 4,874 wounded and was the only service in the battle for which dead exceeded wounded; this was a total higher than all the other wars fought by the U.S. Navy put together. The navy also lost 38 ships sunk and 368 damaged. In the campaign for Okinawa the Japanese lost, to all causes, 6,810 aircraft. Civilians on Okinawa especially suffered. Of the preinvasion population of 450,000, perhaps 94,000 died. At considerable cost, the United States had secured the staging base for the invasion of Japan.

References

Gow, Ian. Okinawa, 1945: Gateway to Japan. Garden City, NY: Doubleday, 1985.

Leckie, Robert. Okinawa: The Last Battle of World War II. New York: Viking, 1995.

Millot, Bernard. Divine Thunder: The Life and Death of the Kamikazes. Translated by Lowell Blair. New York: McCall, 1970.

Inoguchi Rikihei and Nakajima Tadashi, with Roger Pineau. The Divine Wind: Japan’s Kamikaze Force in World War II. New York: Bantam Books, 1978.