The Downfall that never was

How many were killed on the first few days of the Allied invasion of Japan? Tens of thousands of bodies lay mangled on the blood soaked beaches. The sea churned, frothing pink-tinged waves pounding the sticky, red sand. Memories of the D-Day landings were eclipsed by this new slaughter, the desperate defence producing a suicidal savagery that surprised leaders on all sides. Waves of devoted but poorly armed locals had been thrown against the invaders, the feudal mown down by the mechanized as the spirit of the samurai was crushed by the tank.

The Allies moved in wave after wave of reinforcements and eventually secured their beachhead. The vast armies moved on, paying an unthinkable price for each and every mile they captured. Slaughter on this scale brought to mind the Mongol decimation of China or the grinding body count of the Soviet-Nazi clash of ideologies. The invasion would succeed – it had to succeed – but would cost millions of American, British, Soviet, Commonwealth and, of course, Japanese lives. The invasion of Japan became the truly terrifying climax to the deadliest war in history.

By mid-June, the theatre of war had shifted decisively away from Europe into the Pacific. After a bloody and tortuous 82-day campaign, America had captured Ryukyu Islands of Okinawa. The USA was now poised to finish the war against their original enemy and now had the territorial base from which to strike.

Marines burrow in the volcanic sand on the beach of Iwo Jima, as their comrades unload supplies and equipment from landing vessels despite the heavy rain of artillery fire from enemy positions on Mount Suribachi in the background.

The invasion of the Japanese home islands was an awesome and terrifying prospect for the Allied military planners. The Pacific war had become infamous for its savagery and the extreme belligerence of the Japanese forces.

Seizing Okinawa had cost over 12,000 Allied lives whilst almost 100,000 Japanese soldiers fought a desperate and ultimately suicidal defence. The Japanese army and the military clique in control in Tokyo had made it clear that fighting to the death and suicide were the only acceptable alternatives for both its armed forces and civilian populations.

It was assumed that the intensity of fanatical resistance would only increase as the Allies moved to invade the Japanese ‘home islands’ of Kyushu, Honshu, Hokkaido and Shikoku. But what was the alternative if Japan was to be defeated and brought to unconditional surrender?

Plan for Operation Coronet - the invasion of Honshu and the Tokyo metropolitan area

By the middle of August 1945, however, Japan had agreed to an unconditional surrender. Caught in the choking steel collar of America’s naval and aerial blockade, threatened with imminent invasion by the hated communists of the Soviet Union and slowly realizing the awesome impact of atomic warfare as the US unleashed two of its terrible new bombs on Hiroshima and Nagasaki, even Japan’s blinkered ruling class came to accept the end had come.

The Emperor of Japan took to the airwaves, and shakily delivered what became known as the Gyokuon-hōsō, the ‘Jewel Voice Broadcast’, to a shocked and starving nation. Just two weeks later and the first 150 U.S. personnel landed in Atsugi in Kanagawa Prefecture with the USS Missouri just behind.

This peaceful occupation seemed an impossible dream to the military planners working in June 1945. Instead, they were putting together the most ambitious and potentially deadly amphibious assault ever devised. Operation Downfall was the codename for this audacious plan and was divided into two distinct parts: Operation Olympic and Operation Coronet.

USS Bunker Hill hit by two Kamikazes in 30 seconds on 11 May 1945 off Kyushu

In Autumn 1945, Operation Olympic would have seen a vast force invade Kyushu. It would have seen the largest naval armada ever assembled: 42 aircraft carriers, 24 battleships, and 400 destroyers and destroyer escorts. The land forces would have been greater than those deployed in Normandy (14 divisions compared to D-Day’s 12 divisions).

With a stronghold on the home islands, the Allied forces would then turn to Honshu – the heart of Imperial Japan. Operation Coronet planned for an amphibious assault on the Kanto Plain south of Tokyo. With 25 divisions, the combined forces would have been well over double that assembled for the invasion of France.

The planners had no illusions about how difficult the invasion would be. Their assumptions including the following terrifying prospects:

  • Allied forces would be “opposed not only by the available organized military forces of the Empire, but also by a fanatically hostile population”;
  • The invasion forces would face six divisions on Kyushu and up to 21 divisions on Honshu;
  • Japan could withdraw forces from the remnants of her empire, bringing up to 2,500 planes home for the defence.

Although Japan’s armed forces were desperately short of the materiel and natural resources that were essential for modern warfare, no one underestimated the martial spirit of the samurai nation. That ‘hostile population’ was organized into the Patriotic Citizens Fighting Corps, a home guard with a uniquely Japanese flavour. They were armed with muzzle-loading muskets, longbows, or even bamboo spears and were expected to take at least one American soldier with them to the grave.

General Douglas MacArthur signs as Supreme Allied Commander during formal surrender ceremonies on the USS MISSOURI in Tokyo Bay. Behind General MacArthur are Lieutenant General Jonathan Wainwright and Lieutenant General A. E. Percival.

Official estimates of potential Allied fatalities ranged from the optimistic 30,000 to the cataclysmic 500,000 and above. The number of Japanese dead would inevitably have been many times more than that suffered by the Allies.

An indication of the feared casualty rates is shown by the fact that almost 500,000 Purple Heart medals were manufactured in anticipation of mass casualties. The Purple Heart is the American decoration for servicemen wounded in battle. Stockpiled after the peaceful cessation of the conflict, these medals would still continue to be issued almost 70 years later.

American military casualties since the end of the Second World War have not exceeded half a million and the US Army has a store of 100,000 remaining from the original order.