Part 1

Transcriber’s note: Table of Contents added by Transcriber and placed into the public domain. Boldface text is indicated by =equals signs=.

Contents

The Final Campaign: Marines in the Victory on Okinawa Countdown to ‘Love-Day’ Sidebar: The Senior Marine Commanders Sidebar: Initial Infantry Commanders Sidebar: The Japanese Forces L-Day and Movement to Contact The Air and Sea Battles Sidebar: The U.S. Army at Okinawa Sidebar: Marine Air at Okinawa Assault on Shuri Sidebar: Marine Artillery at Okinawa Sidebar: Marine Tanks at Okinawa Closing the Loop Sidebar: Subsidiary Amphibious Landings Legacy Sidebar: For Extraordinary Heroism Sources About the Series About the Author Transcriber’s Notes

THE FINAL CAMPAIGN:

MARINES IN THE VICTORY ON OKINAWA

MARINES IN WORLD WAR II COMMEMORATIVE SERIES

BY COLONEL JOSEPH H. ALEXANDER U.S. MARINE CORPS (RET)

The Final Campaign:

Marines in the Victory on Okinawa

_by Colonel Joseph H. Alexander, USMC (Ret)_

Daybreak on 29 May 1945 found the 1st Marine Division beginning its fifth consecutive week of frontal assault as part of the U.S. Tenth Army’s grinding offensive against the Japanese defenses centered on Shuri Castle in southern Okinawa. Operation Iceberg, the campaign to seize Okinawa, was now two months old--and badly bogged down. The exhilarating, fast-paced opening of the campaign had been replaced by week after week of costly, exhausting, attrition warfare against the Shuri complex.

The 1st Marine Division, hemmed in between two other divisions with precious little maneuver room, had advanced barely a thousand yards in the past 18 days--an average of 55 yards each bloody day. Their sector featured one bristling, honeycombed ridge line after another--sequentially Kakazu, Dakeshi, and Wana (with its murderous, reverse slope canyon). Just beyond lay the long shoulder of Shuri Ridge, the nerve center of the Japanese _Thirty-second Army_ and the outpost of dozens of the enemy’s forward artillery observers who had made life so miserable for American assault forces all month long.

But on this rainy morning, this 29th of May, things seemed somehow different, quieter. After days of bitter fighting, American forces had finally overrun both outposts of the Shuri Line: Conical Hill on the east, captured by the 96th Infantry Division, and the Sugar Loaf complex in the west, seized by the 6th Marine Division. Shuri no longer seemed invincible.

Company A of the 1st Battalion, 5th Marines moved out warily, expecting the usual firestorm of Japanese artillery at any moment. There was none. The Marines reached the crest of Shuri Ridge with hardly a firefight. Astonished, the company commander looked westward along the ridge several hundred yards to the ruins of Shuri Castle, the medieval fortress of the ancient Ryukyuan kings. Everyone in the Tenth Army expected the Japanese to defend Shuri to the death--but the place seemed lightly held. Spiteful small arms fire appeared to come from nothing more than a rear guard. Field radios buzzed with this astounding news. Shuri Castle itself lay beyond division and corps boundaries, but it was there for the taking. The assault Marines asked permission to seize the prize.

Major General Pedro del Valle, commanding the 1st Marine Division, did not hesitate. By all rights the castle belonged to the neighboring 77th Infantry Division and del Valle knew his counterpart, Army Major General Andrew D. Bruce, would be angry if the Marines snatched the long-sought trophy before his soldiers could arrive. But this was an unprecedented opportunity to grab the Tenth Army’s main objective. Del Valle gave the go-ahead. With that, Company A, 1/5, swept west along the ridge against light opposition and took possession of the battered complex. Del Valle’s staff had to do some fancy footwork to keep peace with their Army neighbors. Only then did they learn that the 77th Division had scheduled a major bombardment of the castle that morning. Frantic radio calls averted the near-tragedy just in time. Results of the Marines’ preemptive action incensed General Bruce. Recalled del Valle: “I don’t think a single Army division commander would talk to me after that.”

Notwithstanding this interservice aggravation, the Americans had achieved much this morning. For two months the Shuri Heights had provided the Japanese with superb fields of observed fire that covered the port city of Naha and the entire five-mile neck of southern Okinawa. Even now, as the Marines of A/1/5 deployed into a hasty defensive line within the Castle’s rubble, they were oblivious to the fact that a Japanese rear guard still occupied portions of the mammoth underground headquarters complex directly under their muddy boondockers. They would be astounded to learn that the subterranean headquarters of the _Thirty-second Army_ measured 1,287 feet long and as much as 160 feet deep--all of it dug by pick and shovel.

The Japanese had in fact stolen a march on the approaching Tenth Army. Most of their forces had retreated southwards during the incessant rains, and would soon occupy the third (and final) ring of their prepared, underground defenses, a series of fortified escarpments in the Kiyamu Peninsula.

Seizing Shuri Castle represented an undeniable milestone in the Okinawa campaign, but it was a hollow victory. Just as the flag-raising on Iwo Jima’s Mount Suribachi signified only the end of the beginning of that prolonged battle, the capture of Shuri did not end the fighting. The brutal slugfest on Okinawa still had another 24 days to run. And still the Plum Rains fell, and the horrors, and the dying, continued.

_Countdown to ‘Love-Day’_

The three-month-long battle of Okinawa covered a 700-mile arc from Formosa to Kyushu and involved a million combatants--Americans, Japanese, British, and native Okinawans. With a magnitude that rivaled the Normandy invasion the previous June, the battle of Okinawa was the biggest and costliest single operation of the Pacific War. For each of its 82 days of combat, the battle would claim an average of 3,000 lives from the antagonists and the unfortunate non-combatants.

Imperial Japan by spring 1945 has been characterized as a wounded wild animal, enraged, cornered, and desperate. Japanese leaders knew fully well that Okinawa in U.S. hands would be transformed into a gigantic staging base--“the England of the Pacific”--for the ultimate invasion of the sacred homeland. They were willing to sacrifice everything to avoid the unspeakable disgrace of unconditional surrender and foreign occupation.

Okinawa would therefore present the U.S. Navy with its greatest operational challenge: protecting an enormous and vulnerable amphibious task force tethered to the beachhead against the ungodliest of furies, the Japanese _kamikazes_. Equally, Okinawa would test whether U.S. amphibious power projection had truly come of age--whether Americans in the Pacific Theater could plan and execute a massive assault against a large, heavily defended land-mass, integrate the tactical capabilities of all services, fend off every imaginable form of counterattack, and maintain operational momentum ashore. Nor would Operation Iceberg be conducted in a vacuum. Action preliminary to the invasion would kick-off at the same time that major campaigns in Iwo Jima and the Philippines were still being wrapped up, a reflection of the great expansion of American military power in the Pacific, yet a further strain on Allied resources.

But as expansive and dramatic as the Battle of Okinawa proved to be, both sides clearly saw the contest as a foretaste of even more desperate fighting to come with the inevitable invasion of the Japanese home islands. Okinawa’s proximity to Japan--well within medium bomber and fighter escort range--and its militarily useful ports, airfields, anchorages, and training areas--made the skinny island an imperative objective for the Americans, eclipsing their earlier plans for the seizure of Formosa for that purpose.

Okinawa, the largest of the Ryukyuan Islands, sits at the apex of a triangle almost equidistant to strategic areas. Kyushu is 350 miles to the north; Formosa 330 miles to the southwest; Shanghai 450 miles to the west. As so many Pacific battlefields, Okinawa had a peaceful heritage. Although officially one of the administrative prefectures of Japan, and Japanese territory since being forcibly seized in 1879, Okinawa prided itself on its distinctive differences, its long Chinese legacy and Malay influence, and a unique sense of community.

The Japanese _Imperial General Headquarters (IGHQ)_ in Tokyo did little to fortify or garrison Okinawa in the opening years of the Pacific War. With the American seizure of Saipan in mid-1944, however, _IGHQ_ began dispatching reinforcements and fortification materials to critical areas within the “Inner Strategic Zone,” including Iwo Jima, Peleliu, the Philippines, and Okinawa.

On Okinawa, _IGHQ_ established a new field army, the _Thirty-second Army_, and endeavored to funnel trained components to it from elsewhere along Japan’s great armed perimeter in China, Manchuria, or the home islands. But American submarines exacted a deadly toll. On 29 June 1944, the USS _Sturgeon_ torpedoed the transport _Toyama Maru_ and sank her with the loss of 5,600 troops of the _44th Independent Mixed Brigade_, bound for Okinawa. It would take the Japanese the balance of the year to find qualified replacements.

By October 1944 the U.S. Joint Chiefs of Staff had recognized the paramount strategic value of the Ryukyus and issued orders to Admiral Chester W. Nimitz, Commander-in-Chief, Pacific Fleet/Commander, Pacific Ocean Areas, to seize Okinawa immediately after the Iwo Jima campaign. The JCS directed Nimitz to “seize, occupy, and defend Okinawa”--then transform the captured island into an advance staging base for the invasion of Japan.

Nimitz turned once again to his most veteran commanders to execute the demanding mission. Admiral Raymond A. Spruance, victor of Midway, the Gilberts, Marshalls, Marianas, and the Battle of the Philippine Sea, would command the U.S. Fifth Fleet, arguably the most powerful armada of warships ever assembled. Vice Admiral Richmond Kelly Turner, gifted and irascible veteran of the Solomons and Central Pacific landings, would again command all amphibious forces under Spruance. But Turner’s military counterpart would no longer be the familiar old war-horse, Marine Lieutenant General Holland M. Smith. Iwo Jima had proven to be Smith’s last fight. Now the expeditionary forces had grown to the size of a field army with 182,000 assault troops. Army Lieutenant General Simon Bolivar Buckner, Jr., the son of a Confederate general who fought against U.S. Grant at Fort Donaldson in the American Civil War, would command the newly created U.S. Tenth Army.

General Buckner took pains to ensure that the composition of the Tenth Army staff reflected his command’s multiservice composition. Thirty-four Marine officers served on Buckner’s staff, for example, including Brigadier General Oliver P. Smith, USMC, as his Marine Deputy Chief of Staff. As Smith later remarked, “the Tenth Army became in effect a joint task force under CINCPOA.”

Six veteran divisions--four Army, two Marine--would comprise Buckner’s landing force, with a division from each service marked for reserve duty. Here was another indication of the growth of U.S. amphibious power in the Pacific. Earlier, the Americans had forcibly landed one infantry division at Guadalcanal, two each in the Gilberts, Marshalls, and Palaus, and three each at Saipan and Iwo. By spring 1945, Spruance and Buckner could count on eight experienced divisions, above and beyond those still committed at Iwo or Luzon.

Buckner’s Tenth Army had three major operational components. Army Major General John R. Hodge commanded the XXIV Corps, comprised of the 7th, 77th, and 96th Infantry Divisions, with the 27th Infantry Division in floating reserve, and the 81st Infantry Division in area reserve. Marine Major General Roy S. Geiger commanded the III Amphibious Corps (IIIAC), comprised of the 1st and 6th Marine Divisions, with the 2d Marine Division in floating reserve. Both corps had recent campaign experience, the XXIV in Leyte, the IIIAC at Guam and Peleliu. The third major component of Buckner’s command was the Tactical Air Force, Tenth Army, commanded by Marine Major General Francis P. Mulcahy, who also commanded the 2d Marine Aircraft Wing. His Fighter Command was headed by Marine Brigadier General William J. Wallace.

The Marine components staged for Iceberg in scattered locations. The 1st Marine Division, commanded by Major General Pedro A. del Valle, had returned from Peleliu to “pitiful Pavuvu” in the Russell Islands to prepare for the next campaign. The 1st Division had also been the first to deploy to the Pacific and had executed difficult amphibious campaigns at Guadalcanal, Cape Gloucester, and Peleliu. At least one-third of the troops were veterans of two of those battles; another third had experienced at least one. Tiny Pavuvu severely limited work-up training, but a large-scale exercise in nearby Guadalcanal enabled the division to integrate its newcomers and returning veterans. General del Valle, a consummate artillery officer, ensured that his troops conducted tank-infantry training under the protective umbrella of supporting howitzer fires.

The 6th Marine Division became the only division to be formed overseas in the war when Major General Lemuel C. Shepherd, Jr., activated the colors and assumed command in Guadalcanal in September 1944. The unit may have been new, but hardly a greenhorn could be found in its leadership ranks. Many former Mariner raiders with combat experience in the Solomons comprised the heart of the 4th Marines. The regiment had also landed at Emirau and Guam. The 22d Marines had combat experience at Eniwetok and Guam. And while the 29th Marines comprised a relatively new infantry regiment, its 1st Battalion had played a pivotal role in the Saipan campaign. General Shepherd used his time and the more expansive facilities on Guadalcanal to conduct progressive, work-up training, from platoon to regimental level. Looking ahead to Okinawa, Shepherd emphasized rapid troop deployments, large-scale operations, and combat in built-up areas.

The 2d Marine Division, commanded by Major General LeRoy P. Hunt, had returned to Saipan after completing the conquest of Tinian. There the division absorbed up to 8,000 replacements and endeavored to train for a frustratingly varied series of mission assignments as, in effect, a strategic reserve. The unit already possessed an invaluable lineage in the Pacific War--Guadalcanal, Tarawa, Saipan, and Tinian--and its mere presence in Ryukyus’ waters would constitute a formidable “amphibious force-in-being” which would distract the Japanese on Okinawa. Yet the division would pay a disproportionate price for its bridesmaid’s role in the coming campaign.

The Marine divisions preparing to assault Okinawa experienced yet another organizational change, the fourth of the war. Headquarters Marine Corps (HQMC), constantly reviewing the lessons learned in the war to date, had just completed a series of revisions to the tables of organization and equipment for the division and its components. Although the “G-Series” T/O would not become official until a month after the landing, the divisions had already complied with most of the changes. The overall size of each division increased from 17,465 to 19,176. This growth reflected the addition of an assault signal company, a rocket platoon (the “Buck Rogers Men”), a war dog platoon, and--significantly--a 55-man assault platoon in each regimental headquarters. Artillery, motor transport, and service units received slight increases. So did the machine gun platoons in each rifle company. The most timely weapons change occurred with the replacement of the 75mm “half-tracks” with the newly developed M-7 105mm self-propelled howitzer--four to each regiment. Purists in the artillery regiments tended to sniff at these weapons, deployed by the infantry not as massed howitzers but rather as direct-fire, open-sights “siege guns” against Okinawa’s thousands of fortified caves, but the riflemen soon swore by them.

Headquarters, U.S. Marine Corps, backed up these last-minute changes by providing the quantities of replacements required, so that each assault division actually landed at full tables of organization (T/O) strength, plus the equivalent of two replacement drafts each. Sometimes the skills required did not match the requirement, however. Some of the artillery regiments had to absorb a flood of radar technicians and antiaircraft artillery gunners from the old Defense Battalions at the last moment. But by and large, the manpower and equipment shortfalls which had beset many early operations had been overcome by the time of embarkation for the Okinawa campaign.

Surprisingly for this late in the war, operational intelligence proved less than satisfactory prior to the Okinawa landing. Where pre-assault combat intelligence had been superb in the earlier operations at Tarawa (the apogean neap tide notwithstanding) and Tinian, here at Okinawa, the landing force did not have accurate figures of the enemy’s numbers, weapons, and disposition, or intelligence of his abilities. Part of the problem lay in the fact that cloud cover over the island most of the time prevented accurate and complete photo-reconnaisance of the target area. In addition, the incredible digging skills of the defending garrison and the ingenuity of the Japanese commander conspired to disguise the island’s defenses.

The island of Okinawa is 60 miles long, but only the lower third contained the significant military objectives of airfields, ports, and anchorages. When Lieutenant General Mitsuru Ushijima assumed command of the _Thirty-second Army_ in August 1944, he quickly realized this and decided to concentrate his forces in the south. He also decided, regretfully, to refrain from contesting the likely American landings along the broad beaches at Hagushi on the southwest coast. Doing so would forfeit the prize airfields of Yontan and Kadena, but it would permit Ushijima to conserve his forces and fight the only kind of battle he thought had a chance for the Empire: a defense in depth, largely underground and thus protected from the overwhelming American superiority in supporting arms. This was the attrition/cave warfare of the more recent defenses at Biak, Peleliu, and Iwo Jima. Each had exacted a frightful cost on the American invaders. Ushijima sought to duplicate this philosophy in spades. He would go to ground, sting the Americans with major-caliber gunfire from his freshly excavated “fire-port” caves, bleed them badly, bog down their momentum--and in so doing provide the Imperial Army and Navy air arms the opportunity to destroy the Fifth Fleet by massed _kamikaze_ attacks.

To achieve this strategy, Ushijima had upwards of 100,000 troops on the island, including a generous number of Okinawan conscripts, the Home Guard known as _Boeitai_. He also had a disproportionate number of artillery and heavy weapon units in his command. The Americans in the Pacific would not encounter a more formidable concentration of 150mm howitzers, 120mm mortars, 320mm mortars, and 47mm antitank guns. Finally, Ushijima also had time. The American strategic decisions to assault the Philippines, Peleliu, and Iwo Jima before Okinawa gave the Japanese garrison on Okinawa seven months to develop its defenses around the Shuri epicenter. Americans had already seen what the Japanese could do in terms of fortifying a position within an incredibly short time. At Okinawa, they achieved a masterpiece. Working entirely with hand tools--there was not a single bulldozer on the island--the garrison dug miles of underground fighting positions, literally honeycombing southern Okinawa’s ridges and draws, and stocked each successive position with reserves of ammunition, food, water, and medical supplies. The Americans expected a ferocious defense of the Hagushi beaches and the airfields just beyond, followed by a general counterattack--then the battle would be over except for mop-up patrolling. They could not have been more misinformed.

The U.S. plan of attack called for advance seizure of the Kerama Retto Islands off the southwest coast, several days of preliminary air and naval gunfire bombardment, a massive four-division assault over the Hagushi Beaches (the Marines of IIIAC on the north, the soldiers of XXIV Corps on the south). Meanwhile, the 2d Marine Division with a separate naval task unit would endeavor to duplicate opposite the Minatoga Beaches on Okinawa’s southeast coast its successful amphibious feint off Tinian. Love-Day (selected from the existing phonetic alphabet in order to avoid planning confusion with “D-Day” being planned for Iwo Jima) would occur on 1 April 1945. Hardly a man failed to comment on the obvious irony: it was April Fool’s Day and Easter Sunday--which would prevail?

The U.S. Fifth Fleet constituted an awesome sight as it sortied from Ulithi Atoll and a dozen other ports and anchorages to steam towards the Ryukyus. Those Marines who had returned to the Pacific from the original amphibious offensive at Guadalcanal some 31 months earlier marveled at the profusion of assault ships and landing craft. The new vessels covered the horizon, a mind-boggling sight.