Battle of Okinawa: The Most Intense Battle of WWII’s Pacific Theater

Before the realization of the atomic bomb, the American plan was to invade the Japanese home islands. The expected conclusion to the fighting in the Pacific Theater would not be easy. In fact, it was projected that the Japanese would fight even harder. Against soldiers who were willing to use suicidal waves of kamikaze attacks, the Americans knew that the upcoming battle would be more intense than any they had suffered before.

The start of the plan to invade the Japanese Home Islands entailed the amphibious landing on the island of Okinawa. The bloody fighting that took place informed the Americans that defeating Japan once and for all would be a task of extreme proportions, drenched in blood and misery.

The Battle of Okinawa was a taste of what was to come.

The Americans knew that taking Okinawa, the largest of the Ryukyu Islands, would be a monumental task, and the body count would be extraordinarily high. The island was perfect for the defenders. In the south, there were limestone cliffs, while in the north, the island was filled with rugged hills and ravines.

Additionally, the island had over 400,000 native Okinawans living on it, and the Japanese had prepared them to resist any American attempts at invasion. Through propaganda, the Japanese instilled fear in the Okinawans. This effort was helped by the Americans, who had been bombing the island since September 1944, reducing the capital of Naha to rubble.

The Japanese, being outnumbered, would have to make good use of these natural defenses. They were no strangers to this kind of warfare and had learned lessons from years of fighting against the Chinese on the mainland and the Allies in the Pacific. Mustering around 80,000 soldiers, the Japanese forces were bolstered by another 40,000 Okinawans conscripted to fight against the Americans. These forces also included 1,790 schoolboys aged between 14 and 17.

The American battle order had Vice Admiral Richmond K. Turner in charge until the amphibious landing, at which point Admiral Raymond A. Spruance would take over overall command. Lieutenant General Simon Bolivar Buckner Jr. was in charge of the ground forces.

General Mitsuru Ushijima was in charge of the Japanese 32nd Army, which constituted virtually the entirety of the ground forces.

The American plan called for an amphibious landing on a strip of beaches on the island’s west coast. From there, the American forces would drive inland, capturing the airfields at Yontan and Kadena before venturing north and south.

For this purpose, the Americans would have numerical superiority over the Japanese. One hundred eighty thousand combat troops would be involved, with constant reinforcements boosting the total to 250,000 as the operation dragged on.

The invasion date for “Operation Iceberg” was set for April 1. On March 24, American troops began disembarking on smaller islands around Okinawa in preparation for the invasion. On March 29, the American fleet moved into position and began the bombardment, preparing the way for American troops.

On the morning of April 1, the landing craft sailed towards the beaches on the west coast of Okinawa. Expecting heavy fighting, the American troops were naturally nervous, but they encountered only sporadic resistance when they landed. This landing involved a total of 60,000 American soldiers and marines in what would be the largest amphibious landing of the Pacific Theater during the Second World War.

Admiral Mitsuru Ushijima, in charge of the Japanese forces, had decided not to contest the landings. Knowing his forces would likely be outnumbered, he did not want to waste his soldiers. Instead, he used the island’s natural features to strike where he could and inflict the most damage with minimal losses.

The Japanese had retreated to the mountainous areas of the island, where they had constructed numerous bunkers and tunnel systems.

By April 2, the two airfields near the landing grounds were secured, and American forces continued their push against light Japanese resistance. On April 5, they reached the island’s east coast, effectively splitting the island in two. From this point, the US Army pushed south, and the US Marines pushed north. As they did so, the Japanese resistance began to stiffen, and the illusion of an easy victory for the Americans began to vanish.

On April 6, the Japanese air campaign began, and the American fleet became the target of the mass use of kamikaze attacks launched from Kyushu and Formosa (Taiwan). In addition to the air assault, kamikaze boats were also used. From April 6-7, over 350 kamikaze attacks were made on the American fleet. Despite the ferocity of the kamikaze storm, it was not as effective as the Japanese had hoped.

It is true that a large number of American ships were sunk, but none were larger than a destroyer, leaving fleet carriers, battleships, and cruisers damaged but able to weather the storm intact.

Supported by the wave of kamikaze attacks, the Japanese battleship Yamato entered the fray. The Japanese had also hoped the power of the biggest battleship ever built would turn the tide, but it was an easy target for carrier-based planes. The sinking of the Yamato signaled the end of the era of battleships and Japan’s ability to produce any effective naval resistance to the American fleet.

The advance had been steady in the north, and by April 7, Japanese forces on the Motobu Peninsula had been trapped. This represented the vast majority of the Japanese forces in the north of the island.

On April 13, the Americans had advanced to the northernmost post of the island, Hedo Point. The battle for the Motobu Peninsula ensued and was marked by Japanese suicide attacks.

Meanwhile, the tiny island of Iejima off the coast of the Motobu Peninsula was the site of an amphibious landing by the Americans. Like elsewhere on Okinawa, the defenders used mass waves of suicide attacks. Here, there were also women armed with spears who resisted the American landing. From April 16, the fighting raged on this island before being declared secure on April 21. This was also the site where the American journalist Ernie Pyle was killed by machine gun fire on April 18.

On the Motobu Peninsula, the US forces made significant progress by capturing Mount Yaedake, the main defensive position of the Japanese.

In the south, the American advance was temporarily halted by rugged resistance from the Japanese using the tight-knit ridges to their favor. Despite the advantage of these confined spaces in halting the American advance, they also became deathtraps for the Japanese as they increased the casualty rate from American artillery, which had been brought forward to prepare the American advance.

The fights for Kakazu Ridge, Nishibaru Ridge, and Tombstone Hill ended up becoming a bloodbath, claiming the lives of over 450 American soldiers and over 5,000 Japanese. The casualty rate had a huge impact on Japanese morale, and they fell back further south to a new defensive line, which included the infamous Maeda Escarpment, commonly known as “Hacksaw Ridge,” where the Americans encountered particularly harsh resistance and suffered terrible losses.

This is where the famous Desmond Doss won his Medal of Honor. A conscientious objector, he refused to carry a gun and was inducted into the forces as a medic. On Hacksaw Ridge, he rescued, under fire, countless American and Japanese soldiers who had been wounded. His story was made into a major motion picture released in 2016.

All through April, the US soldiers inched slowly forward, battering against Japanese defenses and fighting through the confines that demanded attrition as the only way to gain victory.

The US advance was halted again, and attrition was so bad that the soldiers had to be rotated out and replaced with Marines. Noticing the American movements, on May 4, the commander of the Japanese forces in the area, Major-General Isamu Chō, ordered an amphibious maneuver to attack the Americans from behind. To support this attempt, the Japanese had to move their artillery out into the open, where they became easy targets for American counter-battery fire. In the end, the attempt to attack the Americans from the rear failed, and the Japanese had to return to a defensive stance and grind down the Americans via attrition.

Monsoon rains throughout the rest of May turned the battlefield to mud, and the scenes became reminiscent of the trenches and no-man’s land of the First World War. Rotting human corpses and garbage littered the ground, and maggots were everywhere, turning the soldiers’ lives into a living hell.

Meanwhile, on the north of the island, constituting some of the last defenders on Motobu Peninsula, a company of Japanese commandos destroyed 70,000 US gallons of fuel and nine planes in a suicide attack before being killed. That same day, the US Marines entered the outskirts of the Okinawan capital of Naha and found it deserted. Carefully, they spread through the city and secured it, which took until May 27.

At the same time, the battleship USS Mississippi opened fire on Shuri Castle two miles to the east of Naha. When the American soldiers reached the castle on May 29, they found it to be deserted. The whole defensive line had been abandoned, and 30,000 Japanese troops had moved south to join up with another 10,000 soldiers, taking up final defensive positions to the southwest of Naha on the Oroku Peninsula.

On June 4, the US launched an amphibious assault on the peninsula. Their first target was the airfield in which 4,000 Japanese sailors were holed up. All 4,000 defenders, including their commander, Admiral Ōta, committed suicide.

What was left of the Japanese army was driven east and south to a small pocket on the south of Okinawa. On June 18, with the conclusion of the battle in no doubt, General Simon Buckner, in overall command of the ground forces, was killed by Japanese artillery fire.

By June 21, the fighting was over. The vast majority of the Japanese forces who were not killed in the fighting, much of it by suicide attacks, committed seppuku. Of all the Japanese commanders, only Colonel Yahara was left alive. Admiral Ushijima had ordered him not to commit suicide, as the Battle of Okinawa needed a witness to be able to tell the story of what had happened.

The high number of suicides was in part due to the belief among the Japanese that the Americans did not take prisoners, and anyone attempting to surrender would be shot on site. The Japanese committed suicide en masse, mostly by jumping off cliffs or shooting themselves.

In total, around 77,000 Japanese soldiers died, with many thousands of Okinawan conscripts joining them. The official US estimate puts the Japanese body count at over 110,000 fighters.

In contrast, the Americans suffered 50,000 casualties, with 12,000 of them being deaths.

During the naval part of the operation, the Japanese launched over 1,000 kamikaze attacks. This represented the biggest usage of such tactics during the entire war.

The Battle of Okinawa was a bloodbath. For such a tiny piece of land, the casualty rate was enormous.

Ultimately, the invasion was mostly unnecessary. The island was invaded out of the need for a foothold from which to launch a campaign against the Japanese Home Islands. This plan never came to fruition, as the atomic bomb would end the war much sooner.