Assault troops of the 1st Marine Division churn ashore aboard a landing vehicle, tracked Mk 3 (LVT[3]) amphibian tractor. This view is toward the amtracs stern and shows a .50cal HB-M2 machine gun. Five-gallon water cans line the amtrac’s sides for use ashore and for protection from small-arms fire. The landings on Okinawa were the largest simultaneous amphibious assault in the entire Pacific War and in total over 1,300 ships would take part. (USMC)
The spring of 1945 found Allied fortunes in the Pacific very much in the ascendant. There was no doubt who would be the ultimate victor. The only questions remaining were when the final battle would be fought and how many more men would have to die.
The Japanese knew what was coming next but they did not know exactly where the Americans would strike. The Imperial General Headquarters (IGHQ) narrowed the possible targets to Formosa off the Chinese mainland or Okinawa southwest of the Home Islands and part of the Ryukyus island group. The Japanese began to reinforce both areas as the American 5th Fleet and US 10th Army marshaled at island bases across the Pacific.
In 1945 only scattered remnants of the Imperial Japanese Army (IJA) held out in the Philippines. Much of the Imperial Japanese Navy (IJN) rested on the bottom of the Pacific. Its once feared carrier air arm had virtually ceased to exist. US submarines had cut Japan’s sea-lanes while B-29 bombers rained explosives on Japan’s cities at will.
Expecting attacks on Formosa and the Ryukyus, Japan prepared to battle the Americans to a stalemate. Hoping that Japanese spirit would endure massed American firepower and limitless material resources, it would strive to inflict unacceptable losses and sue for peace.
The 32nd Army’s battle slogan expressed this plan for a “war of attrition” in blunt terms:
One plane for one warship
One boat for one ship
One man for ten of the enemy or one tank
But the 32nd Army under the command of Lieutenant-General Mitsuru Ushijima was not at full strength and could only defend approximately one-third of the region. The 32nd Army’s deployment found the 62nd Division covering an area in the south from Naha and Shuri north to a line anchored on the east and west coasts on the second narrowest neck of the island, the three-and-a-half-mile-wide Chatan Isthmus. This north-facing front was dug in on some of the first high ground encountered south of the central plains where the Americans would land. A more formidable defense line behind this was centered on the rugged 4,500 yard-long Urasoe–Mura Escarpment, Tanabaru Escarpment, and several ridges running from northwest to southeast across the island. The main defense line, however, was still further south and centered on Shuri Castle and a vast, rugged cross-island ridge and hill complex. The weary advancing Americans would run headlong into well-prepared and formidable defenses.
The 24th Division secured the southern end of the island to prevent landings and act as the 32nd Army reserve. The 44th Independent Mixed Brigade (IMB) was southeast of the 62nd defending the Chinen Peninsula, where it was thought the Americans might land on the island’s southeast Minatogawa Beaches (Minatoga in most US documents). The Okinawa Naval Base Force secured the Oroku Peninsula southwest of the 62nd Division and was prepared to fight the Americans at the water’s edge as was IJN doctrine. The island’s north was not completely abandoned. The 1st Specially Established Regiment (formed from airfield service personnel) screened the Yontan and Kadena Airfields on the central plains. The regimental-size 2nd Infantry Unit, detached from the 44th IMB, was established on the Motobu Peninsula on the island’s northwest coast to distract the Americans. One of its battalions was on Ie Shima (island) just west of the Motobu along with other small elements.
The 32nd Army had little faith in promised Japanese air support. In order to survive and slow the Americans to the maximum extent, the Army would dig. Thousands of pillboxes, bunkers, weapons emplacements, and fighting positions were dug. Terrain features were incorporated into the defense and weapons were well-sited with excellent overlapping fields of fire. Multiple defense lines were established across the island anchored on dominating terrain. Extensive tunnel systems were dug, over 60 miles, enough to protect the Army’s 100,000 troops. The construction and improvement of these repeating lines would continue through the battle as the Japanese were painfully pushed south. Supplies and munitions were protected in dugouts and caves.
The embrasure of a concrete and limestone 10.5cm Model 14 (1925) gun emplacement dug into the side of a hill. Despite having a limited field of fire, it and other widely dispersed guns were able to concentrate their fires on specific areas through which it was predicted the enemy would advance. Similar positions were constructed of logs rather than concrete. (USMC)
This 100ft-long, log-reinforced tunnel had five rooms branching off it. The tunnel was found on Ie Shima, and would have served as a troop shelter, command post, aid station, ammunition and supply store. (USMC)
A heavily constructed concrete, limestone, and log bunker line on Mezado Ridge 500–600 yards southwest of Kunishi and 1,200 yards south of Itoman. Only a direct hit by a large-caliber projectile or a heavy bomb would breach such bunkers. (US Army)
Troops of the 1st Marine Division board a landing craft, vehicle and personnel (LCVP) alongside an assault transport on the morning of L-Day. (USMC)
The main landing would begin at 0830hrs, April 1, 1945, H-Hour, L-Day. The largest simultaneous amphibious assault in the Pacific War would see the landing of two Marine and two Army divisions abreast on eight miles of beach. III Amphibious Corps (IIIAC) would land opposite Yontan Airfield with its 6th Marine Division on the left. The Division would move rapidly inland, seize the airfield and protect the 10th Army’s north flank by severing the island at the narrow Ishikawa Isthmus. Its 22nd Marines would land on the left flank. The 4th Marines would land on the right and would focus on the airfield. The Division’s 29th Marines was in IIIAC Reserve to land to order. On the IIIAC’s right, the 1st Marine Division would storm ashore south of the airfield and maintain contact with XXIV Corps on its right. The 7th Marines would land on the Division’s left and the 5th on the right. The 1st Marines would be in Division Reserve and follow the 7th ashore while the Eastern Islands would be secured as required to further protect the 10th Army’s seaward eastern flank.
The Bishi Gawa (stream) served as the initial physical boundary between IIIAC and XXIV Corps. The veteran 7th Infantry Division would land on the corps’ left, maintain contact with IIIAC, and seize Kadena Airfield. Its 17th Infantry would be on the left and the 32nd on the right. The 184th Infantry was the division reserve. The 96th Infantry Division would land south of the airfield with its 381st Infantry on the left and the 383rd Infantry on the right. Its 382nd Infantry was the corps reserve. There was no division reserve, but the 382nd would land behind the 381st and be prepared to respond to a Japanese counterattack from the south. XXIV Artillery would land as necessary to support the corps attack. The corps’ main mission, after capturing Kadena Airfield, was to swing south and secure an east–west line through Kuba Saki and seal off the Japanese in the south.
The 2nd Marine Division would remain as the 10th Army Floating Reserve along with the 27th Infantry Division as the Expeditionary Troops Floating Reserve.
Map depicting the landing beaches at Okinawa. (Osprey Publishing Ltd.)
Once the island was severed and the Japanese forces divided and isolated, with the central portion of the island secured XXIV Corps would advance south with the 7th Infantry Division on the left (east) and the 96th on the right (west) to seize the main objective area: the island’s southern end. IIIAC would back up XXIV Corps, securing the occupied sector across the island with its 1st Marine Division while the 6th advanced to clear the north end of the island. The 77th Infantry Division would then seize Ie Shima. The 27th Infantry Division would land as necessary as XXIV Corps’ frontline lengthened as the advance pressed south to where the island widened.
Initial air support for the landing forces would be provided by 14 escort carriers. Task Force 51 (TF-51) would transport and deliver the landing forces, sustain them ashore, provide close air support, and deliver naval gunfire support. The 5th Fleet’s Fast Carrier Striking Force (TF-58) and British Carrier Force (TF-57) would attack Japanese air bases in the Home Islands and the Ryukyus and any remnants of the Imperial Fleet.
Rear-Admiral Raymond A. Spruance, as Commander Task Force 50 (TF-50), 5th Fleet and Central Pacific Task Forces, was ultimately responsible for both the Iwo Jima and Okinawa campaigns.
Rear-Admiral Richmond Kelly Turner, as the Joint Expeditionary Force Commander, directed all amphibious landings as he had done at Iwo Jima. Lieutenant-General Simon B. Buckner Jr, the son of a Confederate general, was Commanding General, Expeditionary Troops and 10th Army (TF-56). Three days before the island was declared secure, Buckner would be killed observing his troops’ advance on the final organized resistance.
Major-General John R. Hodge had led XXIV Corps during the bitter campaign for Leyte before returning to Hawaii with the rest of his corps to join the new 10th Army and prepare for the Okinawa assault. Major-General Roy S. Geiger had worked with Hodge on Bougainville and Peleliu as Commander of III Amphibious Corps. With the death of Lieutenant-General Buckner on June 18, 1945, Geiger assumed command of 10th Army for a short while, the only Marine officer to command a field army, while retaining command of IIIAC.
The Imperial Headquarters appointed Lieutenant-General Ushijima as commander of the Japanese 32nd Army on August 8, 1944. The steady and reserved Ushijima selected a very different individual as his chief-of-staff. Major-General Isamu Cho was known for his strong emotions, enthusiasm, and boldness. Cho was the main advocate of the underground defense of Okinawa, but he was also responsible for the disastrous May offensive.
While of comparatively junior rank, an equally important, and unique, member of the 32nd Army staff was Colonel Hiromichi Yahara, the senior operations officer. His higher military education included the Japanese War College. He spent two years as an exchange officer in the United States and was widely recognized as an expert in his field.
As a joint command, TF-51 contained elements from the US Army, Navy, Marine Corps, and the three services’ air arms. TF-51 was itself a component of another task force, TF-50, the 5th Fleet and Central Pacific Forces under Admiral Spruance. Spruance, as the commander tasked with carrying out the invasion, also directly controlled two other task forces participating in the campaign.
From left to right: Admiral Spruance, Commander, Central Pacific Task Forces and 5th Fleet; Fleet Admiral Nimitz, Commander-in-Chief, Pacific Ocean Areas; and Lieutenant-General Simon B. Buckner Jr, Commanding General, 10th Army. (USMC)
The Fast Carrier Force (TF-58), under Vice-Admiral Marc A. Mitscher, had 88 ships including 11 fleet carriers and six light carriers with almost 1,400 aircraft backed by seven battleships, 18 cruisers, scores of destroyers and escorts, and a massive logistics support group. Vice-Admiral Sir Bernard Rawlings’ British Carrier Force (TF-57) contributed four carriers, two battleships, five cruisers, and 14 destroyers plus a fleet train. Most of its 260 aircraft were American-built. Task Force 50 could also depend on support from other commands to include Submarine Force, Pacific Fleet; US Army Air Forces in China, and B-29s of the 20th Air Force flying out of the Marianas.
TF-51, the Joint Expeditionary Force, consisted of five smaller task forces and three task groups under Rear-Admiral Turner. Many of the task force’s Navy units had little respite after the Iwo Jima operation. However, Iwo Jima had allowed the Americans to battle-test their command and communications systems, which put them at the advantage.
A D-18 bulldozer disembarks from a landing craft, tank Mk 6 (LCT[6]). Other engineer equipment would follow. The 119.5ft long craft could carry four medium tanks or 150 tons of cargo. It was armed with two 20mm guns. The stern could be opened and several LCTs could be anchored end-to-end to serve as a floating causeway between shore and an LST, as vehicles could simply drive through the connected craft. (US Army)
The 10th Army was composed of two corps, one Army and the other Marine, and, uniquely, its own tactical air force. It comprized over 102,000 Army troops of which over 38,000 were non-divisional artillery, combat support, and headquarters troops as well as some 9,000 service troops. Over 88,000 Marines were assigned along with 18,000 Navy (mainly Seabees and medical) personnel. 10th Army assault troops, those landing in the initial assault, totaled 182,821 men.
Directly under 10th Army was the 53rd Anti-aircraft Artillery Brigade with five antiaircraft artillery groups, six 90mm, and three 40mm anti-aircraft artillery battalions as well as military police, signal, and medical groups.
XXIV Corps (Southern Landing Force) was under the command of Lieutenant-General Hodge, and already had valuable experience working with Marines V Amphibious Corps (VAC). XXIV Corps Artillery, under Brigadier-General Josef R. Sheetz, had three artillery groups with 14 battalions of various calibers. Four infantry divisions were assigned to XXIV Corps. The reinforced 7th, 77th, and 96th averaged almost 22,000 troops, but each was some 1,000 infantrymen under strength.
The Regular Army 7th Infantry Division which had fought at Leyte also prepared for service on Okinawa. The “Bayonet Division” was commanded by Major-General Archibald V. Arnold.
The 96th Infantry Division, known as the “Deadeye Division” was under the command of Major-General James L. Bradley for its entire World War II service including Okinawa.
The 27th Infantry Division, the floating reserve, would be the next to arrive on Okinawa. It fielded only just over 16,000 troops and was commanded by Major-General George W. Griner Jr.
The last division to land on Okinawa was the 77th Infantry Division, an Army Reserve division. Under the command of Major-General Andrew B. Bruce, the “Statue of Liberty Division” served as the Western Landing Force to first seize islands west of Okinawa.
The Marine Corps’ contribution to 10th Army was III Amphibious Corps under Major-General Geiger. III Amphibious Corps Artillery, under Brigadier-General David R. Nimmer, consisted of two three-battalion provisional groups to support the corps’ two divisions.
Only two Marine divisions were to fight on Okinawa, although a third was to play an important role. Unlike Army divisions, the Marine divisions deployed with 100 percent infantry strength plus 2,500 replacements.
As discussed previously, the 1st Marine Division, the “Old Breed,” was formed February 1, 1942. The division’s more than 24,000 troops were commanded by Major-General Lemuel C. Shepherd Jr. The 2nd Marine Division was formed from the 2nd Marine Brigade on February 1, 1941 at San Diego. Most of the division fought on Guadalcanal in 1942–43 as well as on Saipan and Tinian in the summer of 1944. The 22,000-man division was under the command of Major-General Thomas E. Watson.
The 32nd Army was organized on April 1, 1944, to defend Okinawa, one year to the day before the Americans landed. It was augmented by the 44th IMB although it never achieved full strength.
The 62nd Division, under the command of Lieutenant-General Takeo Fujioka, was also deployed to Okinawa. Roughly 300-man engineer, signal, and transport units completed the 62nd Division along with a field hospital.
The strongest formation on Okinawa was the 24th Division under Lieutenant-General Tatsumi Amamiya. Raised in December 1939, it had seen no combat, but was well trained. Several thousand Okinawan civilians were conscripted into Civil Defense Units and labor units as well as augmenting regular units.
In total, IJA troops numbered 67,000. Of these about 5,000 were Okinawan conscripts assigned to regular Japanese units and about 29,000 32nd Army troops belonged to labor, service, and specialized support units.
Each Marine division had a detachment of 12 1-ton truck-mounted 4.5in rocket launchers organized into two six-truck sections. The crewmen were called “Buck Rogers Men” after a contemporary science fiction hero. Each truck, nicknamed a “Sandy Andy” after a popular toy, mounted three Mk 7 launcher racks with each holding 12 rockets. They could fire 36 high explosive and white phosphorus rockets in four seconds to a range of 1,100 yards. (USMC)
Some 3,825 IJN personnel and over 6,000 civilian combatant employees were also assigned.
Kerama Retto is a group of eight rugged islands 15 miles west of Okinawa. The Keramas would become the fleet’s refueling, rearming, and repair base. The need for such a base was realized during the Iwo Jima assault. Only four of the islands were defended by 975 IJN troops and the islands were easily seized.
Keise Shima, 11 miles southwest of the Hagushi Beaches, was also secured unopposed on March 31. Marine scouts had previously confirmed the islets were unoccupied. The 420th Field Artillery Group came ashore with the 531st and 532nd Battalions to support the main landing and cover southern Okinawa with their 155mm guns.
On March 29 spotter aircraft over Okinawa reported that the entire island appeared deserted. At 1000hrs, March 30, frogmen swam in to demolish anti-boat obstacles. The main assault could now take place.
The amphibious force assembled just west of Okinawa. The Carrier Force took up station some 50 miles to the east. On March 31, the Demonstration Group, 2nd Marine Division, embarked, arriving off the southeast Minatogawa Beaches, which the Japanese considered the most likely site for the main landing. This landing was a diversionary feint. The deception was reinforced by underwater demolition team (UDT) scouts and minesweepers operating offshore since March 29.
April 1, 1945 – L-Day – dawned with only a light swell on the landing beaches. Transports and LSTs dropped anchor three–seven miles offshore. At 0530hrs the pre-landing barrage smothered a zone 1,000 yards inland with some 25 rounds per 100 square yards. As the sun rose behind the hilly island, seasick soldiers and Marines saw smoke-shrouded Okinawa for the first time. At 0800hrs, dozens of LCI(G) gunboats cruised toward the beaches with 3in and 40mm guns blazing. At 0815hrs hundreds of circling Amtracs formed into assault waves.
Control craft pennants came down five minutes later and an eight-mile line of churning Amtracs began their 4,000-yard run to the beaches. Sixty-four carrier planes strafed and bombed the beaches as naval gunfire shifted inland. As four American divisions ran in toward the shore, the 2nd Marine Division at the Minatogawa Beaches executed its feint. Ironically, the first troop casualties were suffered by this force as Kamikazes crashed into a transport and LST. Other than attracting air attacks, the demonstration failed to draw Japanese reinforcements.
The first assault waves landed at 0830hrs – H-Hour – as only sporadic Japanese mortar and artillery fire fell short. Resistance ashore was virtually nil as the untrained 3,473 airfield service troops dissolved. Only half of the unit was armed and there were virtually no heavy weapons. Okinawa was not the feared repeat of Peleliu and Iwo Jima with troops slaughtered on the beaches. Instead, in the first hour 50,000 troops landed. Blasted suicide boats and small craft were found choking the Bishi Gawa separating IIIAC and XXIV Corps zones. As soldiers and marines pressed inland, larger landing craft and ships began delivering divisional artillery and support troops at 1400hrs. The receding tide exposed the reef and the unloading of heavy equipment slowed. Late morning found the 4th Marines on the edge of Yontan Airfield and the 17th Infantry at Kadena. The two airfields were not expected to be captured until L+3.
Troops of the 32nd Infantry, 7th Infantry Division, rest during the push inland toward Kadena Airfield from the “Orange” Beaches, April 1. The man in the foreground carries an M2 tripod for a .30cal M1919A4 machine gun and a 250-round M1 ammunition can. A gas mask case and M1910 pick-mattock are on his left hip. The flame gunner behind him carries an M2-2 flamethrower. (US Army)
By nightfall a 15,000-yard beachhead was firmly established and another 10,000 troops had landed. The four assault divisions reported only 28 dead, 27 missing, and 104 wounded this first day on Okinawa.
On the morning of L+1 the 2nd Marine Division conducted another demonstration off the southeast beaches to no avail, other than allowing Ushijima to claim he had forced their withdrawal. The two airfields were securely in American hands as were the surrounding hills. The defenders failed to place demolitions on the airfields, and by the afternoon of L+1 Kadena was usable for emergency landings with Yontan usable the following day. Meanwhile the main bridge over the Bishi Gawa was captured intact. The question in every one’s mind was, “Where is the enemy?”
Troops marching across Okinawa. The American landings were virtually unopposed, allowing the attackers to gain a 1,500 yard beachhead by the end of the first day. (NARA)
The weather remained favorable for the next two days and the Americans continued their rapid advance. The 6th Marine Division moved north and by April 4 had secured the narrow Ishikawa Isthmus. The 1st Marine and 7th Infantry Divisions reached the east coast on the afternoon of the 3rd and the Marines secured the Katchin Peninsula on the 5th. The 96th Infantry Division wheeled to its right and began moving south as did elements of the 7th on the east coast. By L+3 they were established on a line across the Chatan Isthmus facing south. All units were in positions they had expected to reach after two weeks of hard fighting.
The supply build-up continued and more support units landed. Empty transports departed and each night the fleet dispersed, some fell victim to increasing air attacks, but a picture emerged of a general Japanese withdrawal to the south prior to L-Day.
The weather turned for the worse on April 4 but the American command could only guess at Japanese intentions while air reconnaissance revealed nothing in the south as the Japanese remained underground.
On April 4 General Hodge ordered the 7th and 96th Infantry divisions to attack south. The Japanese plan was to use the 62nd Division to hold the main northern defense line while the 24th Division and 44th IMB were held in reserve to destroy any new American landings on the southern coasts. The 62nd Division and its supporting artillery were in excellent positions on commanding terrain and had clear line of sight across XXIV Corps’ area on the plain below. The 62nd Division’s defense was echeloned with its 63rd Brigade dug in across the island and the 64th defending the west coast on its flank.
The 63rd Brigade put up a stiff enough resistance to halt XXIV Corps elements from April 6–8. The covering force had held the Americans off for eight days inflicting over 1,500 casualties on the corps but at a cost of almost 4,500 dead. The outer Shuri defenses were now uncovered and the corps would continue its advance against even tougher resistance.
The 383rd Infantry, 96th Infantry Division, attacked the 1,000 yard Kakuzu Ridge on April 9 and was repulsed. It was not until April 12, after repeated attacks, that the ridge was finally taken. The defending 63rd Brigade lost 5,750 men, the US 96th Division lost 451. During the battle the 7th Infantry Division had made slow progress in rugged terrain against stiff resistance to the east. The 7th Division’s sector was only one-third of XXIV Corps’ front, but the terrain forced narrow frontages and the almost nonexistent road system hampered logistics.
“While on Okinawa, the marines and soldiers were going through their crucible of hell brought on by rain, heat, poison snakes, mosquitoes … the stench of human feces and rotting human flesh filled with maggots…”
— AN UNKNOWN OKINAWA VETERAN
Chafing at their defensive strategy, the more aggressive Japanese officers clamored for a counterattack. Colonel Yahara held them at bay reasoning that even if a counterattack was successful, the troops would be exposed to massive American firepower on the plains. However, General Ushijima gave in when the Americans became stalled in the outer Shuri defenses.
US Marines with a .30cal M1917 move up on Okinawa Sugar Loaf ridge. (Tom Laemlein)
The counterattack was launched at 1900hrs, April 12 with a 30-minute barrage to cover the infiltration. The attack was far too weak and uncoordinated as many commanders, realizing its folly, held back their troops.
In contrast, the US 96th Infantry Division faced a well-organized and sustained attack. The Japanese 272nd IIB’s attack was well conducted and gave the US 381st Infantry a difficult night on Kakazu Ridge. The battle lasted into the night of April 13/14. But by dawn it was all over. It delayed the American push a couple of days, but the Japanese lost hundreds of men and the Americans less than 100. The Americans continued to inch south and then prepared to assault the main Shuri defenses on even more rugged terrain.
An Army tank company prepares to advance from behind a ridge line. These M4A3 Shermans have had their large white stars painted over in black to prevent them from being used as targets for anti-tank guns. The Japanese 47mm Model 1 (1941) anti-tank gun, while of moderate performance when compared to similar contemporary weapons, was effective against Shermans. (US Army)
While XXIV Corps fought slowly toward Shuri, IIIAC was engaged in a different kind of war. The 1st Marine Division defended Yontan Airfield and the landing beaches, and secured the zone behind XXIV Corps across the island. The 6th Marine Division had secured the Ishikawa Isthmus with the 22nd Marines to the north where the isthmus began to widen. On the morning of April 6 the 29th Marines launched a tank-supported push up the west coast while the 4th Marines moved up the east. The Japanese had blown bridges and laid mines, but resistance was very light. Finally, on April 8, after combing the hills, it was determined the enemy had concentrated on the Motobu Peninsula on the island’s upper west coast. The 29th Marines now moved across the base of the peninsula and westward. Contacts increased over the next few days, but no decisive engagements were fought and enemy resistance, exacerbated by worsening terrain, increased as the Marines moved west.
The enemy was positioned in a redoubt around the 1,200ft-high Yae Take (Mount). The broken ground precluded the use of armor and was ideal for the defenders, the heavily armed 1,500-man “Udo Force” detached from the 44th IMB. Initial skirmishing and maneuvering lasted for days, but on April 14 the attack was begun in earnest by the 29th and 4th Marines. Numerous hills and ridges had to be taken during the approach to Yae Take. The 17th saw the final assault on the Take, but it was not cleared until the next day. Some 700 Japanese dead were counted; although enough managed to escape to conduct a lengthy guerrilla war in the wild north with countless small skirmishes, hit-and-run attacks and sniping taking a heavy toll.
On May 4, the under-strength 27th Infantry Division relieved the 6th Marine Division in the north. The 6th had lost 236 dead and 1,601 wounded. On August 4, the whole of the north was finally declared secure, although small pockets remained. Over 1,000 Japanese had been killed and some 500 prisoners taken.
Ie Shima (frequently called Ie Jima) was codenamed Indispensable. It lies three and a half miles off the west end of the Motobu Peninsula and 20 miles north of the Hagushi Beaches. The north and northwest coasts are faced with cliffs up to 100ft high, pockmarked with hundreds of caves while the south coast is lined with beaches which range in width from 9–35 yards and are broken into sections of between 125 and 900 yards long separated by low cliffs. Thrusting abruptly upward from the east portion of the island is Iegusugu Pinnacle. This is a conical limestone peak 600ft high, honeycombed with caves and ravines reinforced by tunnels and pillboxes. On the Pinnacle’s south side is the sprawling Ie Town of stone buildings. On the island’s center were three 6,000–7,000ft long airfields in the pattern of an “XI.” The island had a population of 8,000, but about 3,000 had been evacuated to Okinawa. Ie Shima was defended by 3,000 troops of the Igawa Unit, augmented by 1,500 armed civilians including women. Substantial defenses were built around the Pinnacle and within Ie Town.
A flame gunner pictured on his advance across Okinawa as the Americans sought to drive the Japanese from the area. (Tom Laemlein)
This map shows the US assault on Ie Shima. (Osprey Publishing Ltd.)
Minna Shima, an islet four miles south of Ie, was secured by Fleet Marine Force, Pacific Reconnaissance Battalion troops on April 12/13 and occupied by the three artillery battalions on the 15th. The 77th Infantry Division was moved from its station 300 miles southeast of Okinawa and assaulted Ie Shima on the morning of April 16 (W-Day) with full naval gunfire support. The 306th Infantry landed on Beach “Green T-1” at 0758hrs (S-Hour) on the southwest end while the 305th Infantry (less 2nd Battalion) hit “Red T-1” and “T-2” on the south-central coast. Initially, as on Okinawa, there was virtually no resistance with the airfields soon overrun as the regiments swept east across the island. Resistance increased the next day as Ie Town was approached. The 307th Infantry (less 1st Battalion) was landed on the morning of April 17 with part of the 706th Tank Battalion on “Red T-3.” By April 18 the troops had closed in on the north, west, and south sides of the town and Pinnacle amid accusations of taking too long to accomplish the mission. The repeated attacks bogged down against fierce resistance, especially in the town’s center around the administrative building, called Government House Hill, and the surrounding high ground known as “Bloody Ridge.” Most of the town was cleared on April 20 but the Pinnacle was not taken until the next day, and resistance continued on its slopes until April 23. Ie Shima was finally declared secure at 1730hrs on April 21, but mopping-up continued until the 26th. The Japanese lost 4,700, including most of the 1,500 armed civilians, and 409 prisoners were taken. About a third of the civilians remaining on the island died. American losses were 218 dead and missing and 900 wounded.
On Okinawa XXIV Corps’ Army divisions were now facing the Japanese main cross-island defense line – the Shuri defenses – built on a series of steep ridges and escarpments to the north of Shuri. The 7th Infantry Division was to the east, the 96th in the center, and the 27th to the west. They had not moved since April 14 as preparations for the April 19 assault were undertaken. The entire Japanese front was still defended by the 62nd Division with its 64th Brigade defending the west and center and the 63rd Brigade the east, well dug in on the hills and ridges with the 44th IMB in the rear.
A preliminary attack was launched by the 27th Infantry Division on the night of April 18 when bridges were secretly built across the Machinato Inlet separating Uchitomari and Machinato on the west coast. The 106th Infantry secured a valuable foothold on the northwest end of the Urasoe-Mura Escarpment and cleared Machinato Village during a bold night infiltration attack.
The main attack was launched at 0640hrs, April 19, after a massive 27-battalion artillery barrage while naval gunfire and aircraft pounded the Japanese rear area. The 7th Infantry Division attacked toward Skyline Ridge, the anchor at the east end of the Japanese line, but was thrown back in most sectors by withering fire. The 96th Infantry Division in the center made little headway against the strongly defended Tombstone and Nishibaru Ridges, barely gaining any ground beyond its start line. The 27th Infantry Division on the west flank merely held its ground on the south side of the Machinato Inlet, but made further gains on the Urasoe-Mura Escarpment. Its attack on the Kakazu Ridge failed, however, when the 193rd Tank Battalion was separated from 1st Battalion, 105th Infantry as they crossed a saddle between Kakazu and Nishibaru Ridges, resulting in the loss of 22 tanks.
For the next week the three divisions continued the effort to push south against well dug-in resistance with no unit gaining more than 1,300 yards. The Bradford Task Force, assembled from reserve battalions of all three divisions in the line, and heavily supported by armor, finally overran the Kakazu Pocket on April 24, but by then the Japanese had abandoned it. The Japanese also lost their one opportunity for a successful counterattack as there were no US reserves; everything had been committed to the line. By the end of the month most units had progressed comparatively well, gaining 1,000–2,000 yards in many areas. The 96th Infantry Division was still held up on its west flank by the Urasoe-Mura Escarpment defended by the Japanese 32nd Infantry. The US 7th Infantry Division had made significant headway on its inland flank, but was held up there on Kochi Ridge by the Japanese 22nd Infantry. Clearly, the divisions were exhausted and their strength low.
1st Marine Division troops on the approaches to Shuri Castle view the carnage and devastation of this hotly contested portion of the battlefield, May 25. (USMC)
It was during this period that it was proposed to execute a flanking landing using the 77th Infantry Division on the southwest coast north of Minatogawa in an effort to force the Japanese to pull troops out of the Shuri defenses. It was rejected by Buckner from April 17–22 as it was too much of a risk to land a single division so far behind Japanese lines, particularly when taking into account the additional logistics burden and the ships required to protect the supporting anchorage.
What looks to be a Japanese civilian emerges from the devastation on Okinawa, surrendering to US Marines. One soldier holds a .45cal pistol. (Tom Laemlein)
The 1st Marine Division was attached to XXIV Corps on April 30, relieving the 27th Infantry Division on the east flank. The 77th Infantry Division, although short by three battalions, was on occupation duty on outlying islands, and relieved the much battered 96th. The assault continued southward through the main Shuri defenses, an effort continued until May 3, when the Japanese attempted their most determined counteroffensive.
Frustrated at the prolonged defensive battle, many Japanese commanders desired a counteroffensive to halt the American advance. Colonel Yahara, 32nd Army operations officer, warned of the folly of such an attack, but Major-General Cho, chief-of-staff, prevailed. The Japanese attacked on the night of May 3 with their main effort made in the center and the east by the 24th Division. The attack was supported by raids conducted by forces landed in the American rear on both coasts. Shallow penetrations were accomplished in some areas, but the attack was repulsed. Japanese losses, some 7,000 of the 76,000-man force, only served to further weaken their front. American units had suffered fewer than 700 casualties and they continued to push south. The counteroffensive was nothing short of a blunder.
The Japanese now rebuilt their units, largely with rear service troops, and prepared for a battle of attrition. The 62nd Division, with only a quarter of its strength surviving, defended the western third of the line while the 24th Division, reduced to two-thirds, defended from north of Shuri to the east coast. The 44th IMB, at four-fifths strength, supported the 62nd Division. Japanese artillery had been cut by half and its daily ammunition allotment drastically reduced.
The Japanese Kamikaze or suicide boats were cheaply constructed plywood boats, which carried a 551lb explosive charge inside the bow. Some had a rack on either side of the cockpit for a 264lb depth charge. The boats were hidden in caves or other camouflaged shelters and moved to launching ramps on a two-wheel cart. The 16–17-year-old volunteers were 2nd and 3rd year officer cadets in the five-year officer academy. If one failed to return from his mission, he was presumed successful and posthumously promoted to lieutenant. The hoped for “blasting to pieces” of the American fleet by “whirlwind” Q-boat attacks never materialized. (Tom Laemlein)
Throughout the campaign TF-51 provided close air support to the troops ashore, combat air patrols to protect from air attacks, interception of Kamikazes, reconnaissance and anti-submarine patrols, logistical support, floating hospitals, continuous gun fire support, and other indispensable services.
The first two weeks of the campaign saw TF-57 (British Carrier Force) operating off Saishima Gunto to neutralize airfields there. Prior to and during the campaign, the 5th and 3rd Fleets’ fast carriers executed attacks throughout the Ryukyus, on Formosa, mainland China, and Kyushu to neutralize Japanese airfields.
Limited Kamikaze attacks were launched during the initial Okinawa landings, but the full fury of the Kamikaze was not felt until a massive 355-plane raid on April 6–7 was unleashed. In 19 hours the Navy suffered six ships sunk and 21 damaged with over 500 casualties. The Japanese lost almost 400 aircraft; Kamikaze and conventional covering fighters. The attacks continued unabated through April with a total of 14 US ships sunk and 90 damaged by Kamikazes, while conventional air attacks sank one and damaged 47. The Japanese paid a price of over 1,100 aircraft. The month of May saw more air attacks, which concentrated on the picket ships, transports, and carriers as well as the American airfields. Especially heavy attacks occurred in late May.
Dark blue-painted F4U-1 Corsair fighters of Marine Fighting Squadron 232 (VMF-232) roll in over southern Okinawa to hit ground targets. Close air support of ground troops was one of the main missions of Marine aviation. (US Army)
Attacks continued to the end of the campaign, with the last launched on June 21–22. In all there were ten main attacks, Sho-Go 1–10, with 1,465 aircraft interspersed with smaller attacks to total about 1,900 aircraft. The result was 26 US ships sunk and 225 damaged by Kamikazes as well as two sunk and 61 damaged by conventional air attack. These attacks on the fleet caused the highest US Navy casualty rate in the war.
In a desperate effort the Japanese sortied the Yamato on April 6 on a suicide mission. The super battleship was to beach itself on Okinawa to the south of the American landing beaches and turn its 18.1in guns on American forces ashore and the transports. There was only enough fuel available for the Yamato and its accompanying ships to make a one-way trip. The Ten-Ichi Operation (“Heaven Number One”) saw the Yamato, the light cruiser Yahagi, and eight destroyers sortie from Tokuyama Naval Base on southwest Honshu. The force was detected by US submarines soon after it entered the open sea but contact was lost during the night as the force turned west. American carrier planes found the Yamato on the morning of April 7 after it had turned southwest toward its target. TF-58 aircraft struck the force at noon, sinking the Yamato, the Yahagi, and four destroyers in two hours at a cost of ten US aircraft. Without air cover the battleship did not even make it halfway to Okinawa and went down with 2,487 crew. Four damaged escort destroyers escaped back to Japan.
“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.”
— LIEUTENANT GENERAL USHIJIMA, IN RESPONSE TO MAJOR YAHARA WHO HAD ASKED FOR PERMISSION TO COMMIT SUICIDE
A gunner of the 22nd Marines, 6th Marine Division, turns a 7.7mm Model 92 (1932) machine gun against its former owners. This was a copy of the British World War I-vintage Lewis machine gun used by the IJN. Its 47-round drum magazines and extra cartons of ammunition lie on the ground. (USMC)
On May 7, IIIAC resumed control of the 1st Marine Division on the west flank. As the Americans pushed south the island widened and it would be necessary to place a fourth division into the line. The 6th Marine Division was soon assigned a sector on the 1st Marine Division’s right and inserted a single regiment, the 22nd, into the line. The 77th Infantry Division was strengthened by the arrival of its under-strength 305th Infantry, relieved from garrisoning Ie Shima. The rested 96th Infantry Division relieved the 7th Infantry Division in the line on May 8 (the surrender of Germany was announced that day). The 10th Army’s renewed offensive began on May 11 with, from east to west, 96th Infantry, 77th Infantry, 1st Marine, and 6th Marine divisions in the line.
On May 22 heavy rains began. After ten days low ground, gullies, and ravines turned into thigh-deep seas of mud. Small streams and rivers overflowed their banks and the already overburdened roads became impassable in many areas.
The primary objective was Shuri. Progress was slow but steady, although the two center divisions had not driven as deeply into the Shuri defenses as those on the flanks. The 6th Marine Division was held up by furious fighting around Sugar Loaf Hill west of Shuri as the other divisions battled for stoutly defended ridges and hills. No complete Japanese unit remained in the lines, only remnants. On May 29 the 22nd Marines took Naha while an element of the 5th Marines, seizing the opportunity, crossed into the 77th Infantry Division’s sector and captured Shuri Castle, much to the Army’s exasperation. On the same date Army units broke through on the east coast as Japanese units were routed creating a melee of intermingled US and Japanese units, with many units at times being attacked from both sides.
On May 25, the Japanese 62nd Division withdrew through a defensive line of the 44th IMB southeast of Naha and then attacked XXIV Corps elements to the east. The Japanese 24th Division then withdrew from that sector on May 29 as the 62nd Division established a new line to the rear. The 24th Division established a new line south of Itoman on the west coast as the 44th IMB withdrew on May 31 to establish a line linked to the 24th Division’s and running to the east coast. The 62nd Division then conducted a fighting withdrawal through the new lines between May 30 and June 4. The 10,000-man Naval Base Force on Oroku Peninsula, misinterpreting the order, withdrew to the south too early on May 28. Dissatisfied with the positions there, they immediately returned to their base, preferring to die defending it rather than to flee alongside the IJA.
The Japanese 32nd Army successfully withdrew to the south, but of the 50,000 troops at the beginning of the operation, only 30,000 remained. Those wounded but capable of action had been left behind to fight to the death with the rearguards, and the severely wounded were killed. The 32nd Army Headquarters left its tunnel command post beneath Shuri Castle on May 27. It established a temporary command post at Tsukazan the next day before moving to a small ridge (Hill 89) near Mabuni on the south coast the day after that. Heavy spring rains began at this time, arriving two weeks later than normal. Rains hindered both sides’ operations, but the vehicle-dependent Americans were hampered most.
On May 24 paratroopers of the Japanese 1st Raiding Brigade attempted an airlanded raid on Yontan Airfield staged from Japan, but only one of the five transports managed to land. A number of US aircraft were destroyed on the ground, but the raiders were quickly killed.
IJN forces still held the Oroku Peninsula on the southwest coast, south of Naha, where the 6th Marine Division was blocked by Naha Harbor. Not to be halted by a mere body of water, the division did what was natural and executed a shore-to-shore amphibious assault launched from the west coast north of Naha and into Naha Harbor to flank enemy forces on the peninsula on June 4 (K-Day).
Marines surround a possible Japanese hideout. Knowing the ground the Japanese had the advantage over the Americans, but, as seen here, the Marines had both firepower and numbers. (NARA)
The 4th Marines landed on Beaches “Red 1” and “Red 2,” south of Naha, at 0600hrs to be followed by the 29th Marines. While not given much attention, the two-regiment subsidiary operation was larger than some earlier amphibious assaults. It was also the last opposed amphibious assault in World War II.
The situation was stabilized by May 31 with most Japanese rear guards positioned in the central portion of the crumbling lines as US forces continued to push south into early June.
After hard fighting, the Japanese remnants were driven to the south end of the island, Kiyan Peninsula, by June 11. There were still substantial pockets in the American rear areas. The Japanese intent now was to hold a line running from south of Itoman on the west coast through the hill masses in the center to a point on the east coast south of Minatogawa, an area approximately five miles across and three deep. The 8th Marines landed at Naha on June 15 and was attached to the 1st Marine Division to assist with the final operations ashore. The 10th Army commander, Lieutenant-General Buckner, was killed observing his troops’ advance against the final organized resistance on June 18. Major-General Roy Geiger assumed command of 10th Army.
The assaulting divisions’ sectors had narrowed to the point that only three to five of the freshest battalions were required in the line. The 7th Infantry Division overran the Japanese 44th IMB’s pocket on Hill 115 southwest of Nakaza on June 17. The US 96th Infantry Division was taken out of the line on June 20 to deal with a large pocket of Japanese 24th Division in the peninsula’s center at Medeera and Makabe. It was not reduced until June 22. As the 6th Marine Division cleared the west coast of the peninsula, the 1st Marine Division wiped out the remaining Japanese 62nd Division pocket just inland of the island’s south end on the Kiyamu-Gusuku Ridge. The 7th Infantry Division closed in on the Japanese 32nd Army’s Headquarters, defended by 24th Division survivors, on a coastal ridge (Hill 89) south of Mabuni. These pockets were largely wiped out on June 21 and Okinawa was declared secure at 1700hrs. Small pockets of resistance remained and the American mopping-up continued for days. At 0340hrs on June 22, Lieutenant-General Ushijima and Major-General Cho committed ritual suicide outside their cave on the south side of Hill 89. The other division and brigade commanders and staffs died during “honorable death attacks” between June 21 and 30.
Kume Shima, 55 miles west of Okinawa, was secured by the Fleet Marine Force, Pacific Amphibious Reconnaissance Battalion, between June 26 and 30 to establish a radar site and fighter direction center. Landing on the island’s southeast coast, the force met no opposition from the estimated 50-man garrison, which was later engaged. This was the final amphibious assault of World War II.
The armed forces of America and Japan had met in an 82-day, no-quarter battle, proving what was already known by both sides: the victor would have to utterly destroy his opponent. Both sides used their resources, whether limited or abundant, to the utmost of their ability to achieve their goals and gain the tactical advantage. Okinawa provided a glimpse of what would have happened if the United States had been forced to invade the Japanese Home Islands.
Only the much larger and longer Philippine Campaign saw higher casualties in the Pacific Theater than Okinawa. Marine ground and air losses were 2,938 dead and missing and 16,017 wounded. The Army lost 4,675 dead and missing and 18,099 wounded. There were over 26,200 US casualties due to combat fatigue, illness, and non-battle injuries. The joint US air services lost 763 aircraft, 458 in combat. US Navy losses were inordinately high with 36 ships sunk and 368 damaged, of which 43 were so badly damaged they were scrapped. These high rates were largely due to the suicide attacks on the fleet. These attacks were also the cause of the Navy’s high casualty rate of the war – 4,900 dead and missing and 4,800 wounded. The British Carrier Force (TF-57) suffered four ships damaged, 98 aircraft lost, 62 killed, and 82 wounded in action.
Over 100,000 Japanese troops and Okinawan Boeitai fought on Okinawa and other islands in the Ryukyus. Estimates of casualties are difficult to determine due to the duration of the action, numbers of enemy forces, inflated reporting of enemy dead, and the nature of combat on Okinawa. The US assessment of Japanese casualties came to over 142,000, more than were on the island. A more realistic assessment is that approximately 66,000 combatants died and half of the survivors were wounded. A total of 7,400 combatants were taken prisoner during the campaign. Some 3,400 unarmed laborers were captured. Large numbers of troops turned themselves in after Japan surrendered. Approximately 10,000 IJA and IJN personnel and 8,000 Okinawan Boeitai and conscripts survived the battle. The Japanese lost 7,830 aircraft; 4,155 in combat, 2,655 operationally, and 1,020 destroyed on the ground on Kyushu and Formosa. Over 4,600 Kamikaze crews died along with hundreds of other pilots. Over 3,650 IJN sailors were lost during the Yamato’s sortie and Japan lost a total of 16 warships during the campaign with four damaged.
At the conclusion of the operation, 42,000–50,000 Okinawan civilians were estimated to have died due to Japanese or American combat action or suicide, or were murdered by the Japanese (to prevent their surrender or to steal their food). Postwar studies found that over 122,000 civilians were killed (almost one-third of the indigenous population and a figure rivaling the combined death toll of over 120,000 at Hiroshima and Nagasaki) and a culture was shattered.
Large numbers of Japanese troops were killed in post-operation mopping-up and additional prisoners were taken, ultimately growing to 16,350 by the end of November 1945. It was the first time that large numbers of Japanese troops willingly surrendered. On August 16, Japan announced its intention to surrender. On August 29, those IJN troops still holding out in the Kerama Retto were among the first Japanese troops to surrender after the announcement. On September 7, five days after the official surrender, the Ryukyu Islands were formerly surrendered at Kadena Airfield to Lieutenant-General Stilwell by Vice-Admiral Tadao Kato and Lieutenant-General Toshiro Nomi (both had been stationed in Sakishima Gunto). There were still approximately 105,000 IJA and IJN personnel on the other Ryukyus islands. Small numbers of Japanese renegades and Okinawan rebels conducted a low-level guerrilla war against US occupation forces into 1947 when the last surrendered.
An IJN lieutenant, commander of the 183rd Naval Attack Force Rifle Battalion, surrenders to the 7th Marines, 1st Marine Division, on Motobu Peninsula, September 3. Japanese Navy field uniforms were a darker green than the olive drab worn by the Army. They were further identified by the yellow anchor insignia on their field caps. (USMC)