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Operation Iceberg: Okinawa April 1945 the Meatgrinder

Mark Caruthers holds a Bachelor's degree in Geography and History from the University of Arkansas (Fayetteville).

Island Hopping Campaign

Okinawa would be the climax of an "island hopping" campaign in the Pacific Ocean that began more than three years earlier. It was the largest and most complex amphibious operation carried out by the American military in the Second World War.

The battle for Okinawa was considered the most fiercely contested action in all the island-hopping campaigns. After the battle American forces were left standing on the very gates of Japan's capital Tokyo located on its main island, Honshu. Until the early fall of 1944, the official Allied strategic plan called for the invasion of Formosa rather than Okinawa mostly due to the fact it was considered an easier nut to crack.

After much debate among Allied leaders the plan to invade Formosa was scrapped in favor of assaulting Okinawa. It was concluded that the occupation of Okinawa would cut off the Japanese home islands from their chief oil supply routes in Burma, Borneo, and Sumatra. It would create a critical fuel shortage for enemy ships and aircraft as the Allied armies war with Japan reached its final stage "Operation Downfall."

Almost six months before the first American ground troops landed on Okinawa, warplanes from carrier Task Force 58 would descend on the island giving its civilians their first horrific taste of what they were to endure in the months ahead.

Early on the morning of October 10, 1944, more than 1,000 Hellcat fighters, Helldiver bombers, and Avenger torpedo bombers from American carriers struck the first major blow to Okinawa's defenses. They would strike targets on Okinawa with more than 500 tons of bombs and thousands of rockets. According to Japanese records 10 transports, thirty merchant ships, and countless other craft were sunk in the harbor of Okinawa's capital, Naha.

General Mitsuru Ushijima (July 31, 1887 – June 22, 1945)

General Mitsuru Ushijima would have his troops lie low for a week on Okinawa until American troops had relaxed their vigilance. And then wage a Holy War on American troops to test their will.

General Mitsuru Ushijima would have his troops lie low for a week on Okinawa until American troops had relaxed their vigilance. And then wage a Holy War on American troops to test their will.


On the Easter Sunday April 1,1945, Allied forces began to land on the Island of Okinawa. It was the opening round for the largest and costliest battle of the Pacific War with over 100,000 Japanese casualties and 50,000 casualties for the Allies.

Two American Marine and Army divisions landed abreast on Okinawa facing an estimated 155,000-armed Japanese armed on the ground. It was the most densely populated island invaded during the Pacific War an estimated 500,000 civilians lived in its cities, towns, and villages.

Thousands of civilians, men and women, would take up arms against the American troops and fight alongside Japanese soldiers. The total number of citizens who died defending Okinawa from the American invasion will never be known, but their contribution to the battle was substantial. Many citizens would commit suicide rather than surrender to American troops.

The invasion code named "Operation Iceberg" was the largest amphibious attack undertaken during the island-hopping operations in the South and Central Pacific during the Second World War. The Allies attacked Okinawa with an overwhelming force of 540,000 men and 1,600 seagoing ships, eclipsing even D-Day in troops, tonnage and firepower.

The American landing was surprisingly easy. Unlike the first hours on Iwo Jima where commanders talked of abandoning the invasion. By 10:00 A.M. on the first day they had reached the edge of Yontan airfield without suffering a single casualty. Just thirty minutes later other troops reached the edge of Kadena airfield. By noon both fields were in American hands. By sunset fifty-thousand American troops were ashore.

There were no Japanese planes in the sky, no submarines, no troops in sight. In the northern sector of the island the marines ran upon just fifteen Japanese soldiers. By mid-afternoon over fifty thousand American troops were ashore, and the supply ships were beginning to unload their cargos, more or less relaxed because the job seemed so easy.

On Okinawa Japanese leaders had completely reversed their tactics. General Ushijima had decided to virtually abandon the airfields and beaches where the Americans would land. Ushijima concentrated his forces in the south and east of Naha, the capital city on the Motobu Peninsula. General Ushijima's troops were so skillfully hidden on the island that the Americans drastically underestimated their numbers. There they remained quietly in their fortified positions as he shells and bombs rained down, to land mostly in the wrong places.

The Japanese troops were hunkered down in a honeycomb of caves and terrain that the U.S. Tenth Army Commander, Lieutenant General Simon Bolivar Buckner, called the most formidable, fixed position in the history of warfare.

Under the organizational name the Tenth Army, Buckner's command was made up of four army and three marine divisions. It was Buckner's first major operation completely under his command. He had led American troops in the recapture of the Alaskan islands of Attu and Kiska in 1942, the only American soil held by Japanese soldiers during the Second World War.

To those few Japanese who believed the war was still winnable, Okinawa was their last chance to stop the Americans, it was the front line of the invasion of their home islands. The island lay within 350 miles of the Japanese homeland and would be used in the future as a base for the follow-on invasion of Japan's southernmost Home Island, Kyushu.

To most Japanese generals Okinawa was nothing more than an attempt to delay the Allied invasion of the Japanese Home Islands as long as possible. Although the Japanese commanders on Okinawa had 155,000 troops to defend the island from invasion, there were not nearly enough troops to defend the ground the way the 23,000 troops defended Iwo Jima.

Japan's Battleship Yamato's Last Mission

In order to put up the best possible defense, the northern half of Okinawa was left almost completely undefended, and the southern half of the island was turned into four extremely tough hedgehog defense sectors, they offered the best prospect of a robust, attritional defense.

The proportion of artillery and mortar to infantry was the highest encountered in Pacific War. For the first time in the Pacific War, the Japanese had ample time to dig elaborate fortifications, much as they had on Iwo Jima, and they also had large numbers of tanks and artillery pieces.

Realizing that he could never defend the entire island, General Mitsuru Ushijima centered his defense around the historical capital, Shuri Castle, a medieval fortress of the ancient Ryukyuan Kings, and its steep limestone ridges on which it was built. This position provided the Japanese with a heavy defense line that could be flanked only from the sea. Since the Okinawan hills had long been used as a major artillery training center, the terrain was familiar to most Japanese gunners, and ranges and coordinates for many potential target areas had already been well established.

The U.S. Navy contributed the bulk of the ships and airplanes in the assault on Okinawa. The total strength of the Allied fleet at Okinawa was over 1,300 ships including 40 carriers, 18 battleships, and 200 destroyers.

The U.S. Navy sustained greater casualties in the assault on Okinawa than any other battle of the war. The Japanese had used kamikaze tactics since the Battle of Leyte Gulf, but for the first time they became a major part of the defense. During the upcoming battle seven major kamikaze attacks were attempted involving over 1,500 planes. The Allied invasion force paid a high price for Okinawa, 79 ships sunk or scrapped, more than 250 damaged, and over 500 aircraft lost.

The most dramatic action of the naval campaign occurred far from the land battle of Okinawa. It involved the attempted kamikaze attack by a strike force of Japanese surface vessels led by the 70,000-ton battleship Yamato, the world's largest battleship. The Yamato and other Japanese surface vessels involved Operation Ten-Go were intercepted shortly after leaving Japanese their ports.

Under attack from more than 300 carrier aircraft, over a two-day span, the Yamato would be destroyed long before she could reach Okinawa. The massive battleship had been ordered to fight her way through enemy naval forces surrounding the island. Afterward run herself onto the beach at Okinawa, then use her guns as artillery to shell Allied positions. After the Yamato was sunk the Japanese Navy ceased operations for the remainder of the war.

Kamikaze War 1944-45

To understand the reasons why so many Japanese airmen were prepared to carry out kamikaze raids you need to understand the past history of the Imperial Air Force. History tells that the kamikaze were two winds or storms that are said to have saved Japan from the Mongol fleets under Kublai Khan. These fleets attacked Japan in the year 1274, and again in 1281. Due to the growth of Zen Buddhism among Samurai at the time in Japan, those events were the first events where typhoons were described as "divine wind" as much by their timing as by their force.

By late 1944, as they attempted to combat the massive Allied juggernaut that was bearing down upon them the Japanese military was a spent force. After suffering a series of devastating defeats defending their Pacific empire, Japan was left unable to stop the American advance on their home island.

At the beginning of the Second World War Japanese aircraft were far superior to the Allied machines. The Zero was an excellent fighter, capable of outmaneuvering and outshooting the slower and older fighters operated by the Americans and British. Japanese dive-bombers, torpedo-bombers and medium bombers were all extremely effective in the early stages of the war.

However, the Allies soon dramatically improved the construction and performance of their aircraft, constantly developing new types and modifications. While the Japanese made slow progress in the design and engineering of new weapons. They suffered increasingly from the lack of raw materials.

The loss of skilled airmen from previous battles such as Midway in 1942, whose expertise was irreplaceable would dramatically weaken effectiveness air forces. While the Allies seemed to have an endless supply of airmen and machines. The gulf grew to such a point between the two advisories that some Japanese pilots were willing to make suicide attacks against American ships, first termed "jibaku" and later known as kamikazes.

Obedient to their Emperor and nation their act served a dual purpose, being effective in battle and setting an example of nobility in death. "We must give our lives to the emperor and country," one kamikaze stated, adding that "This is our inborn feeling."

A strong believer in kamikaze tactics was Admiral Onishi, commander of the First Air Fleet defending the islands of the Philippines. On the 19th of October 1944, he formed a Special Attack Corps, during the Philippines Campaign, as the American Navy surrounded his command.

Onishi understood the dramatic advantage the American forces had at their disposal, he suggested to his pilots that the flight decks of their carriers offered fine targets. The only method that promised success, in his opinion, was suicide missions flown by Zeros carrying 500lb bombs. He told his men that the nation was in great danger and requested their sacrifice "you are already gods," he said, "without earthly desires."

The success of the kamikazes caused Japanese leaders to expand the force. The kamikazes were ten times more effective than conventional raids. It was estimated by Allied commanders if they had invaded the home islands of Japan, they would have over 5,000 kamikazes to meet them as they approached the beaches.

The Shuri Castle

In the ten days between May 11th, and 21st, both sides were locked in the fiercest fighting of the Okinawan campaign. It was hideously reminiscent of the trench warfare on the "Western Front" during the First World War. Okinawa can be compared to trench warfare by its horrible human losses, and the attempt of one side to pierce the defenses of an enemy determined to not yield an inch.

The Japanese on Okinawa refused to give up, often leaving the American troops on the island no choice but to use flamethrowers, or simply blow the cave entrances with explosives, burying the defenders alive.

The Japanese headquarters at Shuri Castle would be eventually taken on May 31, 1945. The commander of the Japanese garrison on Okinawa, Ushijima, committed suicide on June 22,1945, the same day the island was declared secure by American generals.

American forces suffered badly from combat fatigue in the bitter, no-quarter struggle what became known as the "Battle of Okinawa." Few Japanese were prepared to surrender of the 110,000-man garrison on Okinawa only about 7,000 survived to become prisoners of war.

Okinawan civilian deaths in the campaign were in excess of 140,000, it is estimated that more than a third of the surviving civilian population were wounded. Japanese troops treated local civilians brutally using them as slave labor or targets to draw American fire in order to site in their artillery.

Some of the civilians were convinced by Japanese propaganda to believe that American soldiers were barbarians who committed horrible atrocities, killed their families, and themselves to avoid capture. It is believed many Okinawans threw themselves and their family members from cliffs where the Peace Museum now sits. Other Okinawans were murdered by Japanese to prevent their capture or to steal their food and supplies.


Foster, Simon. Okinawa 1945: Final Assault on the Empire. Arms and Armor Press Willers House, 41-47 Strand, London WC2. Sterling Publishing Co. Inc., 387 Park Avenue South, New York, NY. 10016 1994

Leckie, Robert. Okinawa: The Last Battle of World War II. Viking A division of Penguin USA 375 Hudson Street, New York, NY 10014 USA 1995

Ray, John. The Illustrated History of WWII. Weidenfeld and Nicolson The Orion Publishing Group LTD. Orion House 3 Upper Saint Martin's Lane London WC2H 9EA. 2003

Swanston, Alexander. The Historical Atlas of World War II. Chartwell Books 276 Fifth Avenue Suite 206 New York, New York 10001. USA 2008.


MG Singh emge from Singapore on May 12, 2020:

As a air warrior I appreciate this article. It's a great account of a great American victory. The article is exhaustive and gives a great account of one of the important battles in the east.

Mark Caruthers (author) from Fayetteville Arkansas on May 12, 2020:

Lost my Great Uncle in the battle for Okinawa sitting here next to the flag that was used in his final farewell. My grandmother never fully recovered from his lost, I lost her in 2009 so I'm the only one left to carry his flag. The men who fought on Okinawa were some of the bravest men to ever walk this planet. My hat is off to all those who have fought and served for this country as we honor the passage of V-E day.

Jack Burton from The Midwest on May 11, 2020:

My father was a Navy man who was stationed on a landing craft carrying the Marines ashore. He would never talk about Okinawa.

When I was stationed there myself in the Navy in the early 1970s you could still see the American tanks deep in the waters off the coast of Kadena where they misjudged the tide and rolled the tanks off in the high water. My wife and I visited all the places in this article. Suicide Cliff was very sad, where the Japanese soldiers jumped off rather than surrender. Met my wife, who was a young sailor herself, at Kadena AFB. We were married in Naha a few months later. Very fond memories of the island and our time there.

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