Battle of Okinawa

The Battle of Okinawa, codenamed Operation Iceberg, was fought from 1 April to 22 June 1945 and was one of the largest and most destructive engagements of the Pacific War. United States Army and Marine Corps forces, organised under the Tenth Army, assaulted Okinawa with the support of a vast Allied naval armada, while the Imperial Japanese Army and Navy mounted a prolonged and determined defence. The battle took place after a long campaign of island-hopping operations and was intended to secure Okinawa as the principal staging area for the planned invasion of the Japanese home islands. Its ferocity, high casualties and extensive use of kamikaze attacks earned it the epithet “the typhoon of steel”, known in Japanese as tetsu no bōfū.

Strategic Context and Allied Planning

Okinawa was the final and most formidable objective of the Allied advance across the Central and South-West Pacific. Its capture would provide extensive anchorage facilities, forward airfields such as Kadena, and logistical support points for Operation Downfall, the proposed Allied landing on Japan’s main islands. To accomplish this, the United States created the Tenth Army, an integrated Army–Marine force commanded initially by Lieutenant General Simon Bolivar Buckner Jr. This formation comprised the 7th, 27th, 77th and 96th Infantry Divisions, together with the 1st, 2nd and 6th Marine Divisions, and operated with its own tactical air arm and extensive logistical and medical support.
Allied naval power assembled for the campaign was immense. The United States Fifth Fleet, later redesignated the Third Fleet, fielded multiple task forces including fast carriers, escort carriers, battleships, cruisers and scores of destroyers. The British Pacific Fleet added further carrier capacity, contributing five fleet carriers, six escort carriers, two fast battleships, four light cruisers and 12 destroyers, supported by 251 carrier-based aircraft. Australian, New Zealand and Canadian ships reinforced this combined fleet.
The landings were preceded by the capture of the Kerama Islands on 26 March 1945, which provided secure anchorages and an intermediate base for minesweeping and rescue operations.

Japanese Forces and Defence Strategy

The Japanese defence of Okinawa was undertaken by the Thirty-Second Army, commanded by Lieutenant General Mitsuru Ushijima. This force originally comprised the 9th, 24th and 62nd Divisions and the 44th Independent Mixed Brigade, although the 9th Division was redeployed to Taiwan before the battle. The garrison amounted to approximately 67,000 to 77,000 regular army troops, supplemented by 9,000 naval infantry and around 39,000 Okinawan conscripts, including the Boeitai militia and labour units. Japanese planners anticipated an amphibious assault of up to six American divisions, each possessing vastly more firepower than their Japanese counterparts.
Strategic differences emerged within Japanese command. Colonel Hiromichi Yahara, chief of operations, advocated a defensive attrition strategy based on entrenched positions in the rugged southern terrain. Lieutenant General Isamu Chō preferred offensive action. Ushijima ultimately favoured Yahara’s approach, resulting in a layered defensive system centred on fortified ridgelines, caves and tunnels.
A further aspect of Japanese defence was the extensive mobilisation of Okinawan students. Approximately 1,780 schoolboys were pressed into frontline service as the Iron and Blood Imperial Corps, and thousands of female students formed the Himeyuri nursing units. Many were exposed to frontline combat, with significant casualties.

The Invasion and Ground Campaign

The American assault began on 1 April 1945, following intensive naval and air bombardment. Initial landings met little resistance, as Japanese defenders had withdrawn to prepared positions in the south. Tenth Army units advanced rapidly inland, but as they approached the Shuri Line complex of fortifications they encountered fierce resistance. Fighting became a prolonged siege-like contest involving heavy artillery, armour and close-quarter infantry assaults.
In the north, Colonel Takehido Udo led Japanese units in delaying actions, but organised resistance was weaker than in the south. The southern campaign, by contrast, evolved into the bloodiest ground struggle of the Pacific War. Japanese troops resisted tenaciously around Kakazu Ridge, Shuri Castle and the Oroku Peninsula, often fighting to the last man. The death of Ushijima and Chō in June signalled the collapse of organised Japanese resistance.

Naval and Air Operations

The naval aspect of the battle was unprecedented in scope. American and British carrier forces conducted continuous air operations for more than two months, making the battle the longest sustained carrier campaign of the war. Japanese air opposition was initially limited, but by early April Japan launched mass kamikaze raids. Between 1 April and 25 May, seven major kamikaze offensives involving more than 1,500 aircraft were directed against Allied ships.
Allied naval losses were severe. The United States lost 13 destroyers, 15 amphibious ships and 8 other vessels, with 386 ships damaged. 763 Allied aircraft were destroyed. British carriers, protected by armoured decks, withstood kamikaze strikes, though several were damaged. Total Allied casualties were between 76,000 and 84,000, including naval, ground and air forces.
Japanese losses were catastrophic. The Imperial Japanese Army Air Service deployed 850 kamikaze aircraft, while naval forces attempted desperate sorties, most notably Operation Ten-Go, which led to the sinking of the battleship Yamato. Ground casualties included approximately 76,000 Japanese soldiers and an estimated 40,000 Okinawan conscripts, though civilian losses were even higher. At least 149,000 Okinawan residents were killed, forced to commit suicide or reported missing.

Aftermath and Significance

The capture of Okinawa provided the Allies with vital airfields, staging areas and naval bases close to Japan, facilitating blockades and preparations for Operation Downfall. However, the scale of casualties and the ferocity of Japanese resistance raised grave concerns about the projected cost of invading the home islands.
The battle also left deep scars on Okinawan society. The widespread mobilisation of civilians, the use of children in military roles and the devastation of local communities contributed to long-lasting trauma and cultural loss.
In strategic terms, the Battle of Okinawa marked the culmination of the Pacific ground war. It demonstrated both the effectiveness of Allied joint operations and the grim determination of Japanese defensive tactics. The battle’s human cost and operational lessons influenced the final decisions of the war’s closing months and have since made Okinawa one of the most studied and somberly remembered battles of the twentieth century.