The Battle of Okinawa: Course and Consequences

The 1945 Battle of Okinawa was a major combined air, land and sea operation in the US advance towards Japan. Between Kyushu and Taiwan, Okinawa's airfields, harbours and maritime position could strengthen blockade and air attacks and provide forward bases for a proposed invasion of the home islands. The US plan to seize positions in the Ryukyus was Operation Iceberg.

The principal US ground force was Simon Buckner's Tenth Army, comprising the Army's XXIV Corps and the Marines' III Amphibious Corps. Naval forces supplied transport, gunfire and air support. Japan's Thirty-Second Army was commanded by Mitsuru Ushijima, with Chief of Staff Isamu Chō and operations officer Hiromichi Yahara helping shape defence. The main Japanese forces concentrated around Shuri in the south, using ridges, limestone caves and underground works to prolong resistance.

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On 26 March, US forces began landing in the Kerama Islands west of Okinawa, securing anchorages and logistical support for the main fleet. On 1 April, Army and Marine forces landed near the mouth of the Bishi River on the main island's west coast, taking Yontan and Kadena airfields that day. Light beach resistance did not mean the main Japanese forces had collapsed; it reflected their defensive deployment in depth in the south.

US troops then crossed the island and advanced separately north and south. Japanese planners initially hoped troops and artillery protected underground would survive bombardment and wear down the Americans once they entered fortified areas. Rapid loss of airfields contrasted with the prolonged struggle for Shuri, shifting the campaign from beach seizure to successive southern defensive lines.

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From April, southward-moving US forces met fierce resistance on heights including Kakazu and Maeda. Caves and reverse-slope positions prevented heavy bombardment from destroying the whole defensive system at once. Infantry, tanks and artillery had to coordinate repeated advances. Japanese commanders debated attritional defence versus offensive action; their decisions were not consistently uniform.

On 4 May, the Thirty-Second Army launched a major counteroffensive to reverse its situation. It failed to drive back US troops and instead lost men and artillery, leading Ushijima to halt the attack. US forces continued pressing Shuri from both flanks. In late May, Japanese commanders decided to retreat to the southern tip. Withdrawal did not immediately dissolve the army; relocated troops organized new defensive lines there.

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Support at sea also came at a cost. Japan organized air attacks from Kyushu, Taiwan and elsewhere, using special-attack aircraft to strike ships and try to sever US supply. Radar-picket vessels and ships at anchor faced repeated attacks, forcing the fleet to divide effort among transport, air defence and support ashore.

On 7 April, US carrier aircraft attacked the battleship Yamato and its accompanying force heading towards Okinawa, sinking Yamato. The British Pacific Fleet attacked airfields in the Sakishima Islands to suppress Japanese aviation. Air attacks inflicted serious Allied losses but did not deprive US troops on Okinawa of naval support.

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In June, fighting reached areas around Yaese, Yoza and Mabuni, as Japanese command and supply systems progressively broke down. Buckner was killed while observing near the front on 18 June, and Roy Geiger temporarily assumed command. Ushijima and Chō died by suicide in the campaign's final phase. Some remnants continued fighting, while others surrendered or hid.

On 22 June, US forces held a flag-raising ceremony marking the end of organized resistance. Mopping-up operations continued through the end of the month, and the Ryukyus campaign was declared ended on 2 July. These milestones mean different things: a ceremony, commanders' deaths and the cessation of every shot on the island cannot be assigned to one day.

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Civilians suffered shelling, air raids and ground combat, as well as Japanese military requisitions of labour, food and shelter. Many families fled south or hid in caves without adequate food, medical care or safe routes. The intermingling of soldiers and civilians made conditions especially dangerous as the southern defences collapsed. Survivors often entered US-controlled areas carrying little more than a few clothes.

Studying mass deaths described as 'collective suicide' in the Keramas and elsewhere, historian Masaaki Aniya stresses the combined effects of Japanese military coercion and inducement, prohibitions on surrender, cooperation by local leaders and fear of captivity. Explaining these events simply as voluntary suicide erases coercive wartime relationships and the circumstances of victims including children.

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US military government began administering civilians before fighting ended, establishing camps, registering residents, distributing food and arranging medical care. Many early camps were extremely rudimentary, lacking shelter and clothing. Local people were appointed as camp leaders to help with registration, rationing and labour assignments, but ultimate control remained with the occupying forces.

Arnold Fisch's military-government history notes that post-war difficulties were not caused only by combat. Base construction bulldozed additional houses, occupied level agricultural land and damaged irrigation and erosion-control works. Looting by servicemen and frequent camp relocations compounded losses. Residents received relief but could not always return to their villages or restore farming. Okinawa entered a period in which military occupation and base construction became intertwined.

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