Hell on Earth: the brutal Battle of Okinawa

Okinawa lay in a critical position within the Pacific, and the island was located just 550 kilometres from Kyushu, the southernmost of Japan's home islands.

Control of Okinawa would give the Allies an airbase for bombers and fighters to strike the Japanese mainland directly.

The island also offered a large harbour suitable for assembling fleets for the planned invasion of Japan, known as Operation Downfall, and American planners regarded Okinawa as essential for cutting off Japanese shipping routes and tightening the naval blockade. 

The attack on Okinawa followed the success of the Allies' island-hopping campaign, which had seen them seize key positions across the Pacific.

Victories in the Mariana Islands, Iwo Jima, and the Philippines had left Japan increasingly isolated.

By early 1945, the United States Navy and Air Force had gained superiority in the region, and Okinawa’s size and location made it a perfect staging ground for the final assault on Japan.

However, American forces expected a fierce battle because the island formed part of Japan’s inner defensive ring. 

The Japanese high command also understood Okinawa’s value. Military leaders believed that inflicting heavy casualties on the Americans at Okinawa might discourage an invasion of the home islands.

To this end, Japanese forces on Okinawa prepared extensive fortifications that were intended to delay the Allied advance and bleed the attackers.

The island’s terrain of ridges, caves, and coral escarpments gave a strong advantage to defenders who were willing to fight to the death. 

American forces landed on Okinawa on 1 April 1945 after weeks of naval bombardment and air attacks.

The invasion force eventually included more than 180,000 troops during the initial landings, though over 500,000 personnel took part in the wider campaign.

They were supported by a fleet of about 1,300 ships. The fleet included nearly 40 aircraft carriers and ranked among the largest fleets of the war.

The initial landings met little resistance because the Japanese had withdrawn to strong defensive positions inland, and American commanders initially believed that the battle might be easier than expected.

Their optimism quickly ended as the troops pushed south into the main defensive line. 

These main Japanese defensive positions centred on the Shuri Line, a network of bunkers, tunnels, and artillery positions carved into the hills.

The defenders launched ferocious counterattacks, which included mass infantry charges and sniper ambushes.

The Americans advanced slowly under heavy fire and in appalling conditions, as persistent heavy rain turned the battlefield into a sea of mud that made movement difficult and created a breeding ground for disease.

Lieutenant General Simon Bolivar Buckner Jr., commander of US ground forces on Okinawa, directed the campaign until he was killed by enemy artillery on 18 June.

He became the highest-ranking American officer to die in combat during the war. 

The Japanese military also used kamikaze tactics extensively at Okinawa as waves of suicide aircraft targeted American ships, sinking dozens and damaging many more.

On 6 April, the battleship Yamato sailed on a one-way mission to attack the invasion fleet, but she was sunk the following day after carrier aircraft from Task Force 58 launched hundreds of planes against her.

More than 3,000 sailors died in the attack, leaving Japan without its last great battleship.

The kamikaze campaign caused serious losses to the US Navy, which suffered about 4,900 dead and the sinking of 36 ships.

By late May, American forces had finally broken through the Shuri Line after weeks of brutal combat.

The Japanese continued to resist in scattered pockets across the island, and General Mitsuru Ushijima, commander of the Japanese 32nd Army, and his chief of staff, Lieutenant General Isamu Cho, ordered their men to fight to the last.

On 22 June, both men committed ritual suicide as their forces collapsed. The battle officially ended soon afterwards, but the destruction of Okinawa was almost total. 

Japanese forces fought with determination because they regarded Okinawa as a vital part of their homeland.

Soldiers had been told that surrender was dishonourable and that capture meant torture or death.

Propaganda instilled a belief that dying for the emperor would bring glory to their families, and officers enforced strict discipline that punished desertion or surrender with execution.

The mindset created a fighting force that refused to give up, even when surrounded. 

Also, the defensive tactics on Okinawa relied on fortified caves and underground tunnels that had been built to withstand artillery and aerial bombardment.

American troops had to clear each cave and bunker with grenades, flamethrowers, and close-quarter fighting.

The defenders launched ambushes and then retreated through tunnels to strike again.

As a result, every hill became a deadly obstacle that cost lives to capture and slowed the Allied advance to a crawl.

The final stages of the battle even saw one of the last large-scale banzai charges of the war as Japanese troops made desperate final attacks. 

The Battle of Okinawa caused appalling casualties for Allied forces. More than 12,000 Americans were killed and over 49,000 were wounded.

Many soldiers suffered from diseases such as malaria, dysentery, and trench foot because of the filthy battlefield conditions.

Sailors on the invasion fleet endured weeks of kamikaze attacks that killed thousands and left many more maimed or burned. 

Civilians on Okinawa suffered terribly during the campaign as well. The island’s population of around 300,000 found themselves caught between the two armies.

Japanese soldiers often forced civilians to fight or act as human shields, and many civilians committed suicide by jumping from cliffs or using grenades after being told that the Americans would murder them if captured.

Historians estimate that around 100,000 civilians died during the battle, which meant an overwhelming proportion of the island’s population was lost. 

The battle ended in June 1945 with the island in Allied hands but victory came at a terrible price.

The devastation on Okinawa left much of the island in ruins, and civilians who survived faced homelessness and hunger that spread disease.

The United States turned Okinawa into a major military base, by establishing Kadena Air Base, which became one of the largest American installations in Asia and remained occupied long after the war ended. 

For the Allies, Okinawa proved the difficulty of defeating a determined Japanese defence.

The severe casualties influenced American leaders when they debated how to force Japan’s surrender, and President Harry Truman and his advisers feared that an invasion of the home islands would result in 250,000 to 400,000 American deaths.

The experience at Okinawa became a major factor in the decision to use atomic bombs on Hiroshima and Nagasaki in August 1945.