The Battle of Okinawa, also known as Operation Iceberg, was fought on the Ryukyu Islands of Okinawa and was the largest amphibious assault in the Pacific Theater of World War II. The 82 day battle lasted from late March through June 1945.
The battle has been referred to as the "Typhoon of Steel" in English, and tetsu no ame ("rain of steel") or tetsu no bōfū ("violent wind of steel") in Japanese. The nicknames refer to the ferocity of the fighting, the intensity of gunfire involved, and sheer numbers of Allied ships and armored vehicles that assaulted the island. The battle has one of the highest number of casualties of any World War Two engagement: the Japanese lost over 100,000 troops, and the Allies (mostly United States) suffered more than 50,000 casualties, with over 12,000 killed in action. Hundreds of thousands of civilians were killed, wounded or attempted suicide. Approximately one-fourth of the civilian population died due to the invasion.
The main objective of the operation was to seize a large island only 340 miles away from mainland Japan. After a long campaign of island hopping, the Allies were approaching Japan, and Okinawa would serve as a springboard for the planned invasion of the mainland islands. Although hastily converted to a base for air operations, the atomic bombings of Hiroshima and Nagasaki caused Japan to surrender just weeks after the end of the fighting at Okinawa and the invasion never took place.
The Japanese land campaign (mainly defensive) was conducted by the 67,000-strong (77,000 according to some sources) regular Thirty-Second Army and some 9,000 Imperial Japanese Navy (IJN) troops at Oroku naval base (only a few hundred of whose had been trained and equipped for ground combat), supported by 39,000 drafted local Ryukyuan people (including 24,000 hastily-conscripted rear Home Guard militia called Boeitai and 15,000 non-uniformed laborers). In addition, 1,500 middle school senior boys organized into frontline-service "Iron and Blood Volunteer Units", while 600 Himeyuri Students were organized into a nursing unit. The 32nd Army initially consisted of the 9th, 24th, and 62nd Divisions, and the 44th Independent Mixed Brigade. The 9th Division was moved to Taiwan prior to the invasion, resulting in shuffling of Japanese defensive plans. Primary resistance was to be led in the south by Lieutenant General Mitsuru Ushijima, his chief of staff, Lieutenant General Isamu Chō and his chief of operations, Colonel Hiromichi Yahara. Yahara advocated a defensive strategy, whilst Chō advocated an offensive one. In the north, Colonel Takehido Udo was in command. The IJN troops were led by Rear Admiral Minoru Ota.
Staff officers on Okinawa felt as though their headquarters had abandoned them and that, eventually, they would be overwhelmed and destroyed by the Americans. They expected the Americans to land six to ten divisions against the Japanese garrison of two and a half divisions. The staff calculated that superior quality and numbers of weapons gave each U.S. division five or six times the firepower of a Japanese division. To this would be added the Americans' abundant naval and air firepower.
The British Pacific Fleet (BPF) was assigned the task of neutralizing the Japanese airfields in the Sakishima Islands, which it did successfully from March 26 until April 10. On April 10, attention was shifted to airfields on northern Formosa. The force withdrew to San Pedro Bay on April 23. Although by then a commonplace event for the U.S. Navy, this was the longest time that a Royal Naval fleet of that size had been maintained at sea.
On May 1, BPF returned to action, subduing the airfields as before, this time with naval bombardment as well as aircraft. Several kamikaze attacks caused significant damage, but since the British used armored flight decks on their aircraft carriers, they only experienced a brief interruption to their force's objective.
In the three-month battle for Okinawa, the Japanese flew 1,900 kamikaze missions, sinking dozens of Allied ships and killing more than 5,000 U.S. sailors at the cost of 1,465 expended kamikaze planes (2,200 other Japanese and 763 U.S. aircraft were also destroyed, including during the land battle). The ships lost were smaller vessels, particularly the destroyers of the radar pickets, as well as destroyer escorts and landing ships. While no major Allied warship was lost, several fleet carriers were severely damaged. Land-based motorboats were also used in the Japanese suicide attacks.
The protracted length of the campaign under stressful conditions forced Admiral Chester W. Nimitz to take the unprecedented step of relieving the principal naval commanders to rest and recuperate. Following the practice of changing the fleet designation with the change of commanders, U.S. naval forces began the campaign as the U.S. Fifth Fleet under Admiral Raymond Spruance, but ended it as the U.S. Third Fleet under Admiral William Halsey.
Operation Ten-Go (Ten-gō sakusen) was the attempted attack by a strike force of Japanese surface vessels led by the battleship Yamato, commanded by Admiral Seiichi Itō. This small task force had been ordered to fight through enemy naval forces, then beach themselves and fight from shore using their guns as artillery and crewmen as naval infantry. The Yamato and other vessels in Operation Ten-Go were spotted by submarines shortly after leaving Japanese home waters, and were attacked by U.S. carrier aircraft.
Under attack from more than 300 aircraft over a two day span, the world's largest battleship sank on April 7 1945, long before she could reach Okinawa. U.S. torpedo bombers were instructed to only aim for one side to prevent effective counter flooding by the battleship's crew, and hitting preferably the bow or stern, where armor was believed to be the thinnest. Of the Yamato's screening force, the light cruiser Yahagi, and four out of the eight destroyers were also sunk. In all, the Imperial Japanese Navy lost some 3,700 sailors killed, including Itō, at the cost of merely 10 U.S. aircraft and 12 airmen.
The first Americans ashore were soldiers of the 77th Infantry Division, who landed in the Kerama Islands (Kerama Retto), 15 miles (24 km) west of Okinawa on March 26 1945. Subsidiary landings followed, and the Kerama group was secured over the next five days. In these preliminary operations, the 77th Infantry Division suffered 31 dead and 81 wounded, while Japanese dead and captured numbered over 650. The operation provided a protected anchorage for the fleet and eliminated the threat from suicide boats.
On March 31 Marines of the Fleet Marine Force Amphibious Reconnaissance Battalion landed without opposition on Keise Shima, four islets just eight miles (13 km) west of the Okinawan capital of Naha. 155 mm Long Toms went ashore on the islets to cover operations on Okinawa.
The main landing was made by XXIV Corps and III Amphibious Corps on the Hagushi beaches on the western coast of Okinawa on L-Day, April 1, which was both Easter Sunday and April Fools' Day in 1945. The 2nd Marine Division conducted a demonstration off the Minatoga beaches on the southeastern coast to confuse the Japanese about American intentions and delay movement of reserves from there.
Tenth Army swept across the south-central part of the island with relative ease by World War II standards, capturing the Kadena and the Yomitan airbases. In the light of the weak opposition, General Buckner decided to proceed immediately with Phase II of his plan—the seizure of northern Okinawa. The 6th Marine Division headed up the Ishikawa Isthmus. The land was mountainous and wooded, with the Japanese defenses concentrated on Yae-Take, a twisted mass of rocky ridges and ravines on the Motobu Peninsula. There was heavy fighting before the Marines finally cleared the peninsula on April 18.
Meanwhile, the 77th Infantry Division assaulted Ie Shima, a small island off the western end of the peninsula on April 16. In addition to conventional hazards, the 77th Infantry Division encountered suicide bombers, and even Japanese women armed with spears. There was heavy fighting before Ie Shima was declared secured on April 21 and became another air base for operations against Japan.
Few U.S. soldiers encountered the feared Habu snake and soon discarded the cumbersome leggings designed to protect them from snakebite.
While the Marines cleared northern Okinawa, XXIV Corps wheeled south across the narrow waist of Okinawa. The 7th and 96th Infantry Divisions encountered fierce resistance from Japanese troops holding fortified positions on high ground and engaged in desperate hand to hand combat in west-central Okinawa along Cactus Ridge, about five miles (8 km) northwest of Shuri. By the night of April 8 the XXIV Corps had cleared these and several other strongly fortified positions. They suffered over 1,500 battle casualties in the process, while killing or capturing about 4,500 Japanese, yet the battle had only just begun, for it was now realized they were merely outposts guarding the Shuri Line.
The next American objective was Kakazu Ridge, two hills with a connecting saddle that formed part of Shuri's outer defenses. The Japanese had prepared their positions well and fought tenaciously. Fighting was fierce. Japanese soldiers hid in fortified caves armed with hidden machine guns and explosives; American forces often lost many men before clearing the Japanese out from each cave or other hiding place. The Japanese would send the Okinawans at gunpoint out to acquire water and supplies for them, which induced casualties among civilians. The American advance was inexorable but resulted in massive casualties sustained by both sides.
As the American assault against Kakazu Ridge stalled, General Ushijima, influenced by General Chō, decided to take the offensive. On the evening of April 12 32nd Army attacked American positions across the entire front. The Japanese attack was heavy, sustained, and well organized. After fierce close combat the attackers retreated, only to repeat their offensive the following night. A final assault on April 14 was again repulsed. The entire effort led 32d Army's staff to conclude that the Americans were vulnerable to night infiltration, but that their superior firepower made any offensive Japanese troop concentrations extremely dangerous, and they reverted to their defensive strategy.
The 27th Infantry Division, which had landed on April 9 took over on the right, along the west coast of Okinawa. General Hodge now had three divisions in the line, with the 96th in the middle, and the 7th on the east, with each division holding a front of only about a mile and half.
Hodge launched a new offensive of April 19 with a barrage of 324 guns, the largest ever in the Pacific Ocean Theater. Battleships, cruisers, and destroyers joined the bombardment, which was followed by 650 Navy and Marine planes attacking the enemy positions with napalm, rockets, bombs, and machine guns. The Japanese defenses were sited on reverse slopes, where the defenders waited out the artillery barrage and aerial attack in relative safety, emerging from the caves to rain mortar rounds and grenades upon the Americans advancing up the forward slope.
A tank assault on Kakazu Ridge, launched without sufficient infantry support in the hope of a breakthrough, failed with the loss of 22 tanks. Although flame tanks cleared many cave defenses, there was no breakthrough, and the XXIV Corps lost 720 killed, wounded or missing. The losses might have been greater, except for the fact that the Japanese had practically all of their infantry reserves tied up farther south, held there by another feint off the Minatoga beaches by the 2d Marine Division that coincided with the attack.
At the end of April, the 1st Marine Division relieved the 27th Infantry Division, and the 77th Infantry Division relieved the 7th. When the 6th Marine Division arrived, III Amphibious Corps took over the right flank and Tenth Army assumed control of the battle.
On May 4 32nd Army launched another counteroffensive. This time Ushijima attempted to make amphibious assaults on the coasts behind American lines. To support his offensive, the Japanese artillery moved into the open. By doing so they were able to fire 13,000 rounds in support but American counter-battery fire destroyed 19 guns on May 4 and 40 more over the next two days. The attack was a complete failure.
Buckner launched another American attack on May 11. Ten days of fierce fighting followed. On May 13 troops of the 96th Infantry Division and 763d Tank Battalion captured Conical Hill. Rising above the Yonabaru coastal plain, this feature was the eastern anchor of the main Japanese defenses and was defended by about 1,000 Japanese. Meanwhile, on the opposite coast, the 6th Marine Division fought for "Sugar Loaf Hill". The capture of these two key positions exposed the Japanese around Shuri on both sides. Buckner hoped to envelop Shuri and trap the main Japanese defending force.
By the end of May monsoon rains which turned contested slopes and roads into a morass exacerbated both the tactical and medical situations. The ground advance began to resemble a World War I battlefield as troops became mired in mud and flooded roads greatly inhibited evacuation of wounded to the rear. Troops lived on a field sodden by rain, part garbage dump and part graveyard. Unburied Japanese bodies decayed, sank in the mud, and became part of a noxious stew. Anyone sliding down the greasy slopes could easily find their pockets full of maggots at the end of the journey.
On May 29, Major General Pedro del Valle, commanding the 1st Marine Division, ordered Company A, 1st Battalion, 5th Marines to capture Shuri Castle. Seizure of the castle represented both strategic and psychological blows for the Japanese and was a milestone in the campaign. Del Valle was awarded a Distinguished Service Medal for his leadership in the fight and the subsequent occupation and reorganization of Okinawa. However the castle was outside the 1st Marine Division's zone, and only frantic efforts by the commander and staff of the 77th Infantry Division prevented the Marines from being subjected to an American air strikes and artillery bombardment.
Either by design or the "fog of war", Buckner did not detect the Japanese general retreat to their second line of defense in the Kiyan Peninsula, which ultimately led to the greatest slaughter on Okinawa in the latter stages of the battle, including the deaths of thousands of civilians.
On June 4, only some 30,000 poorly-armed (most of their heavy and even personal weapons lost during the withdrawal) soldiers were left in then 32d Army, including few (20%) surviving trained combat troops. In addition, there were 9,000 IJN troops supported by 1,100 militia holed-up at the fortified area of the Okinawa Naval Base Force in the Oroku Peninsula.
Ushijima and Chō committed suicide by seppuku in their command headquarters on Hill 89 in the closing hours of the battle. Major Yahara had asked Ushijima for permission to commit suicide, but the general refused his request, saying, "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. This is an order from your army Commander. Yahara was the most senior officer to have survived the battle on the island, and he later authored a book entitled The Battle for Okinawa.
General Buckner's decision to attack the Japanese defenses head-on, although proving to be extremely costly in U.S. lives, was ultimately successful. Just four days from the closing of the campaign, General Buckner was killed by Japanese artillery fire while inspecting his troops at the front line. He was the highest-ranking U.S. officer to be killed by enemy fire during the war. The day after, a second general, Brigadier General Claudius M. Easley, was killed by machine gun fire.
At sea 368 Allied ships (including 120 amphibious craft) were damaged while another 36, including 15 amphibious ships and 12 destroyers were sunk during the Okinawa campaign. In the end more than 4,900 officers and men of the Navy lost their lives, largely as a result of Japanese kamikazes. The Japanese lost 16 ships sunk, including the enormous battleship Yamato.
On land the U.S. forces lost at least 225 tanks and many LVTs destroyed while eliminating 27 Japanese tanks and 743 artillery pieces (including mortars, anti-tank guns, and anti-aircraft guns), some of them knocked-out by the naval and air bombardments.
By one count, there were about 107,000 Japanese combatants killed and 7,400 captured. Some of the soldiers committed seppuku or simply blew themselves up with hand grenades. In addition, about 20,000 were sealed in their caves alive.
This was also the first battle in the war in which surrendering Japanese were made into POWs by the thousands. Many of the Japanese prisoners were native Okinawans who had been impressed into the Army shortly before the battle and were less imbued with the Japanese Army's no-surrender doctrine. When the American forces occupied the island, the Japanese took Okinawan clothing to avoid capture and the Okinawans came to the Americans' aid by offering a simple way to detect Japanese in hiding. The Okinawan language differs greatly from the Japanese language; with Americans at their sides, Okinawans would give directions to people in the local language, and those who did not understand were considered Japanese in hiding who were then captured.
At some battles, such as at Iwo Jima, there had been no civilians involved, but Okinawa had a large indigenous civilian population and, according to various estimates, somewhere between 1/10 and 1/3 of them during the battle. Okinawan civilian losses in the campaign were estimated to be between 42,000 and 150,000 dead (more than 100,000 according to Okinawa Prefecture). The U.S. Army figures for the campaign showed a total figure of 142,058 civilian casualties, including those who were pressed into service by the Japanese Imperial Army.
In its history of the war, the Okinawa Prefectural Peace Memorial Museum presents Okinawa as being caught in the fighting between America and Japan. During the 1945 battle, the Japanese Army showed indifference to Okinawa's defense and safety, and the Japanese soldiers used civilians as human shields against the Americans. Japanese military confiscated food from the Okinawans and executed those who hid it, leading to a mass starvation among the population, and forced civilians out of their shelters. Japanese soldiers also killed about 1,000 Okinawans who still spoke a different local dialect in order to suppress spying. The museum writes that "some were blown apart by shells, some finding themselves in a hopeless situation were driven to suicide, some died of starvation, some succumbed to malaria, while other fell victim to the retreating Japanese troops." Soldiers on both sides also raped Okinawan civilians and rape by the Japanese troops "became common" in June after it became clear that the Japanese Army had been defeated.
With the impending victory of American troops, civilians often committed mass suicide, urged on by the fanatical Japanese soldiers who told locals that victorious American soldiers would go on a rampage of killing and raping. Ryukyu Shimpo, one of the two major Okinawan newspapers, wrote in 2007: "There are many Okinawans who have testified that the Japanese Army directed them to commit suicide. There are also people who have testified that they were handed grenades by Japanese soldiers (to blow themselves up). Some of the civilians, having been induced by Japanese propaganda to believe that U.S. soldiers were barbarians who committed horrible atrocities, killed their families and themselves to avoid capture. Some of them threw themselves and their family members from the cliffs where the Peace Museum now resides.
However, despite being told by the Japanese military that they would suffer rape, torture and murder at the hands of the Americans, Okinawans "were often surprised at the comparatively humane treatment they received from the American enemy. According to Islands of Discontent: Okinawan Responses to Japanese and American Power by Mark Selden, the Americans "did not pursue a policy of torture, rape, and murder of civilians as Japanese military officials had warned. A Japanese American Military Intelligence Service combat translator with the U.S. military, Teruto "Terry" Tsubota, convinced hundreds of civilians to not kill themselves and thus saved their lives.
Ninety percent of the buildings on the island were completely destroyed, and the lush tropical landscape was turned into "a vast field of mud, lead, decay and maggots".
The military value of Okinawa "exceeded all hope". Okinawa provided a fleet anchorage, troop staging areas, and airfields in close proximity to Japan. After the battle, the U.S. cleared the surrounding waters of mines in Operation Zebra, occupied Okinawa, and set up the United States Civil Administration of the Ryukyu Islands, a form of military government. Significant U.S. forces remain garrisoned there, and Kadena remains the largest U.S. air base in Asia.
Some military historians believe that Okinawa led directly to the use of the atomic bomb on Hiroshima and Nagasaki. A prominent holder of this view is Victor Davis Hanson, who states it explicitly in his book Ripples of Battle:
In 1945, Winston Churchill called the battle "among the most intense and famous in military history."
In 1995, the Okinawa government erected a memorial named Cornerstone of Peace in Mabuni, the site of the last fighting in southeastern Okinawa. The memorial lists all the known names of those who died in the battle, civilian and military, Japanese and foreign. As of June 2008 it contains 240,734 names.
There is ongoing major disagreement between Okinawa's local government and Japan's national government over the role of the Japanese military in civilian mass suicides during the battle. In March 2007, the national Ministry of Education, Culture, Sports, Science and Technology (MEXT) advised textbook publishers to reword descriptions that the embattled Imperial Japanese Army forced civilians to kill themselves in the war so they would not be taken prisoner by the U.S. military. MEXT preferred descriptions that just say that civilians received hand grenades from the Japanese military.
This move sparked widespread protests among the Okinawans. In June 2007, the Okinawa Prefectoral Assembly adopted a resolution stating, "We strongly call on the (national) government to retract the instruction and to immediately restore the description in the textbooks so the truth of the Battle of Okinawa will be handed down correctly and a tragic war will never happen again.
On September 29, 2007, about 110,000 people held the biggest political rally in the history of Okinawa to demand that MEXT retract its order to textbook publishers on revising the account of the civilian suicides. The resolution stated: "It is an undeniable fact that the 'multiple suicides' would not have occurred without the involvement of the Japanese military and any deletion of or revision to (the descriptions) is a denial and distortion of the many testimonies by those people who survived the incidents.
On December 26, 2007, MEXT partially admitted the role of the Japanese military in civilian mass suicides. The ministry's Textbook Authorization Council allowed the publishers to reinstate the reference that civilians "were forced into mass suicides by the Japanese military," on condition it is placed in sufficient context. "It can be said that from the viewpoint of the (Okinawa residents), they were forced into the mass suicides," the council report stated. That was, however, not enough for the survivors who said it is important for children today to know what really happened.
Nobel Prize winning author Kenzaburō Ōe has written a booklet which states that the mass suicide order was given by the military during the battle. He was sued by the revisionists, including a wartime commander during the battle, who disputed this and wanted to stop publication of the booklet. At a court hearing on November 9, 2007, Ōe testified: "Mass suicides were forced on Okinawa islanders under Japan's hierarchical social structure that ran through the state of Japan, the Japanese armed forces and local garrisons. On March 28, 2008, the Osaka Prefecture Court ruled in favor of Ōe stating, "It can be said the military was deeply involved in the mass suicides." The court recognized the military's involvement in the mass suicides and murder-suicides, citing the testimony about the distribution of grenades for suicide by soldiers and the fact that mass suicides were not recorded on islands where the military was not stationed.