鋼の雨: The Battle of Okinawa

US Marines engage IJA troops on Okinawa. (Britannica)

By the spring of 1945, WWII was drawing to a close in Europe. The Axis in that region were either on the run (the Germans) or had already switched sides (the Italians). As Allied command began talking of dividing up liberated Europe in the wake of the Normandy landings, Pacific command was still locked in a brutal struggle with the Imperial Japanese Army (IJA). Having seized most of the Pacific islands and parts of China during the 1930s and early 1940s, the IJA presented a formidable threat to the Allies. Knowing they faced a far from defeated enemy willing to die before giving up, the Allies began planning what was to become one of the bloodiest battles of the war: the Battle of Okinawa, or “Steel Rain” (鋼の雨) as the IJA called it.

ASAP: American hopes for a quick victory were ruined by fanatic Japanese resistance. The savagery of Okinawa helped convince Truman to nuke Japan.

Read on for details!
A map of Allied landing locations on Okinawa. (Wikimedia Commons)

Lead-up to Battle

Following the Japanese attacks on Pearl Harbour in 1941, the Americans led the charge in the Pacific against the Japanese. They were, of course, joined by lesser-known allies from Britain and the Commonwealth as well as fighters from the Pacific nations. Having beaten down the Japanese Navy during the Battle of Midway earlier on in the war, and made bloody progress advancing from island-to-island towards Japan, the Allied force now had Okinawa – a small island 550 km (340 miles) from Japan – in their sights. Okinawa would enable the Allies to launch air strikes on mainland Japan with greater ease and practice for the inevitable landings on Japan. The Ryukyuan inhabitants of the island – who had been treated pretty poorly by the IJA during their occupation – were to suffer the greatest losses during the upcoming battle.

An American naval vessel bombards inland positions during the Battle of Okinawa. (Flickr)

The assault was to be the largest amphibious landing of the Pacific campaign. Landing craft would be driven largely by British and Canadian crews, and the bulk of the fighting force – the “tip of the spear” – was to be comprised of roughly 250,000 soldiers and Marines from the XXIV Corps (Army) and III Amphibious Corps (Marines). They were supported by the Naval Fifth Fleet, and all were commanded by American Admiral Chester W. Nimitz. Nimitz, an imaginative submarine specialist, had proved himself an expert at coordinating combined-arms (naval, aerial and ground) forces against the tenacious IJA. They faced off against nearly 100,000 defenders; 76,000 were experienced and motivated IJA men, and 20,000 were Okinawans forced to wear Japanese uniforms. They were commanded by Lieutenant General Mitsuru Ushijima. Allied doctrine advocated for a 3:1 numerical advantage of attackers to defenders, and as such the assault presented a significant risk for Nimitz. Okinawa’s numerous caves and pre-built tunnel systems – as well as gusuku castles with high walls – meant that the IJA defenders were extremely well dug-in by the time the Allies arrived.

Japanese Kamikaze pilots prior to their “divine wind” suicide missions. (Welt.de)

The Battle

Beginning in February of 1945, Allied ships had been repeatedly targeted by over 1,465 concerted kamikaze (or divine wind) attacks. These attacks were conducted by specially selected pilots who were trained to ram their Zero planes into enemy ships. Concurrently, a Japanese naval fleet codenamed Ten-gō sakusen (Operation Ten-Go) attempted to sneak up on Allied vessels preparing for the invasion of Okinawa. Led by the Yamato – the world’s largest battleship – Ten-Go was ambushed by the Americans. On April 7th, Ten-Go had been effectively destroyed and Yamato was sunk. This proved to be a huge loss for the Japanese, whose naval force had been slated to defend the island. As they had been previously during the campaign, the Allies were able to predict Japanese naval movements thanks to top secret signal interceptions.

The massive Yamato at sea. (Wikimedia Commons)

Near the end of March, Marines and soldiers of the 77th Infantry had begun landing on some of the small islands surrounding Okinawa. While a fake landing was made towards the south of the island, the main force landed in the north on April 1st. They pushed inland across the rocky ground and captured several crucial airfields with limited opposition at first, and by April 18th, the remaining IJA troops in the north were surrounded on the Motobu Peninsula. IJA special suicide troops codenamed Giretsu Kuteitai (“Heroic Paratroopers”) were dropped in to sabotage Allied fuel dumps, but their entire company was wiped out quickly.

Marines return fire at IJA snipers as they advance across the blasted Okinawan landscape. (Flickr)

Concurrently, another American landing group had swung south and began engaging IJA defenders along Highway 1. From there, they pushed on towards the heights of Shuri, site of an old Ryukyuan Castle which was heavily defended. Towards the end of April, the American advance had stalled and the tenacious IJA – and their unwilling Okinawan allies – clung to their positions. The Americans had been surprised at how well the Japanese were able to resist huge artillery bombardments by disappearing into caves and emerging after the firing had stopped. The blasted earth, hammered by naval artillery, only made it easier for the deafened Japanese soldiers to find cover. But my May 11th, American troops had captured two important hills, codenamed “Sugar Loaf” and “Conical”; these two positions flanked Shuri, and allowed the Americans to bring more fire to bear on the IJA positions. After a heavy bombardment from American ships off the Okinawan coast, Shuri was captured by a force of US Marines on May 29th. Although fighting continued, the loss of Shuri seemed to represent a strong psychological blow to the IJA.

An IJA soldier hurls a grenade at enemy troops. (Pinterest)

The Tide Turns

By June 21st, the IJA had been pushed back to their command post on Hill 89 and were forced to hide in underground tunnels. Knowing they had been defeated, Japanese command prepared to commit suicide. One man, Colonel Yahara, was apparently ordered to stay alive by his commanding officer:

“If you die there will be no one left who knows the truth about the battle of Okinawa. Bear the temporary shame, but endure it.

Lieutenant General Mitsuru Ushijima

The battle was over on June 22nd after 81 days of fighting. Most of Okinawa now resembled a WWI battlefield; constantly hammered by artillery, drenched by relentless rains and blasted with flamethrowers, the earth looked more like a foreign planet than earth. As the rains continued, corpses emerged from the earth. Over 100,000 Japanese soldiers, sailors and pilots had been killed, or committed suicide; roughly 15,000 Americans were lost, and men who had served in Okinawa suffered the highest rate of psychological damage out of any battle in the Pacific theatre. The few Japanese men who survived probably experienced the same difficulties.

The most hard-hit of all were the Ryukyuans who lived on Okinawa. Many had been forced to wear IJA uniforms, and were shot by American troops; others had been used as human shields. As the battle wore on, many Okinawan women were sexually assaulted by Japanese troops, a custom established during the Rape of Nanking in China. As the Americans advanced, the IJA spread rumours that the Okinawans would be massacred by the enemy troops, and as such, thousands jumped from the cliffs to their deaths. According to current estimates, almost 100,000 Okinawans were killed by the Japanese and Americans during the battle, or one third of the prewar population.

A wounded Marine receives plasma during May of 1945. (Flickr)


By all accounts, the Battle of Okinawa was a decisive Allied victory. Japanese naval capabilities had been wrecked during the Ten-Go operations, and many of the most talented remaining IJA commanders had perished in the caves under Hill 89. To Allied command, Okinawa represented the stepping-stone to mainland Japan, a key staging area where aircraft could refuel and men could prepare for battle. But according to some, the devastating losses suffered by both sides convinced American president Harry Truman to drop atomic bombs on Japan and “save American lives” by doing so. Victory in Europe had been declared as VE Day on May 8th, and the Allies were quickly losing steam. If the Battle of Okinawa had one main strategic impact – beyond the obvious and horrendous devastation of the unwilling Ryukyuan participants – it was convincing American command to use “the bomb”.

ASAP Notes

In a hurry? Here are the ASAP notes on this topic.

  • Who? 250,000 American Marines and soldiers under Admiral Chester W. Nimitz, supported by Commonwealth troops. They faced off against over 100,000 Imperial Japanese Army (IJA) troops under Lieutenant General Mitsuru Ushijima. Notably, over 20,000 of the IJA force were Okinawan residents – including children – forced to don Japanese uniforms.
  • Where? Okinawa, one of the Ryukyu Islands of Japan. 550 km (340 miles) from the mainland.
  • When? From April 1st to June 22nd, 1945 – 81 days. (Naval battles leading up to the main action commenced in late March).
  • What? The battle was a series of engagements on land, sea and air over the important airfields on Okinawa. Japanese naval vessels were destroyed at sea as the American ground force landed and pushed north and south. The north was captured quickly, but fighting in the centre and south of the island dragged on for months. After the capture of Shuri (an ancient castle and dominating position), IJA resistance collapsed and thousands of Japanese soldiers – and Okinawans – committed suicide.
  • Why? Okinawa was seen as a vital stepping stone to mainland Japan, and a training ground for the main invasion. The battle took longer than expected due to the fanatical Japanese resistance.
  • Result: Decisive Allied victory. It was the bloodiest battle in the Pacific theatre, and possibly resulted in American president Truman’s decision to drop the atomic bombs on Japan.

Food for Thought

Like what you’ve read? Here are a couple essay questions/prompts to get you thinking. Good writing is all about answering questions the reader didn’t know they had, after all. These questions are to inspire further research, help with an academic paper, or maybe just get you thinking more about the topic.

  • Was the Battle of Okinawa necessary? Could the island have been bypassed by the Allies?
  • What was the Okinawan situation prior to the battle? How were they treated within the hierarchy of Japanese society, and how did Okinawan society rebuild after the fighting stopped?
  • What were the key Japanese mistakes, and how did the Allies exploit them?
  • Assess Nimitz’ handling of combined arms assets (air, ground and sea).
  • What has been the legacy of the battle for Okinawans in the decades after?

Further Reading & Citations

Here are a couple useful sources for further reading or using to flesh out an essay. Remember to cite everything properly!

  • Leckie, Robert. 1995. Okinawa: the last battle of World War II. New York: Viking.
  • Tzeng, Megan. “The Battle of Okinawa, 1945: Final Turning Point in the Pacific.” The History Teacher 34, no. 1 (2000): 95-117.
  • Sarantakes, Nicholas Evan. “Warriors of Word and Sword: The Battle of Okinawa, Media Coverage, and Truman’s Reevaluation of Strategy in the Pacific.” The Journal of American-East Asian Relations 23, no. 4 (2016): 334-67
  • Pearson, R. (1996). The Place of Okinawa in Japanese Historial Identity. In D. Denoon, M. Hudson, G. McCormack, & T. Morris-Suzuki (Eds.), Multicultural Japan: Palaeolithic to Postmodern (Contemporary Japanese Society, pp. 95-116). Cambridge: Cambridge University Press.
  • Yahara, Hiromichi, and Frank Gibney. 1995. The battle for Okinawa. New York: J. Wiley.

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