Operation Downfall

1. Lead

Operation Downfall was the Allied plan to invade Japan in 1945 and 1946, and it was the largest amphibious operation ever planned. The plan called for two invasions: Operation Olympic, the invasion of the southern island of Kyushu in November 1945, and Operation Coronet, the invasion of the main island of Honshu, near Tokyo, in March 1946. Together, the two operations would have involved more than 5 million Allied soldiers, sailors and airmen, more ships than the Normandy landings, and more casualties than any battle in American history. The invasion never happened. It was cancelled in August 1945, after the atomic bombings of Hiroshima and Nagasaki and the Soviet invasion of Manchuria, when Japan surrendered. Downfall is therefore a battle that was never fought, and it is remembered as the invasion that the atomic bomb made unnecessary — and as the measure of what the war would have cost if it had gone on.

Downfall matters because it is the counterfactual against which the end of the Second World War is judged. The men who planned the invasion expected it to be the bloodiest campaign of the war: the Japanese, who had fought to the death at Iwo Jima and Okinawa, were expected to fight to the death for their home islands, and the Americans, who had lost 12,000 men killed at Okinawa, expected to lose far more in Japan. The estimates of American casualties for Olympic alone ran from 250,000 to more than a million, and the estimates of Japanese casualties — military and civilian — ran into the millions. The atomic bombs, which killed about 210,000 people at Hiroshima and Nagasaki, are often judged against those estimates, and the debate about whether the bombs were necessary is, at its heart, a debate about Downfall: about whether the invasion would have cost more lives than the bombs did, and about whether Japan would have surrendered without them.

The plan itself was a remarkable document, and it tells us much about the state of the war in the summer of 1945. The Americans, who had conquered the Pacific island by island, were confident they could conquer Japan, but they were not confident about the cost. The Japanese, who had lost their navy and their air force, were preparing to defend their home islands with everything they had: with the army, with the navy, with the air force, and with the civilian population, armed with bamboo spears and trained to die for the Emperor. The invasion that never happened was the largest operation ever planned, and its cancellation was the end of the Second World War.

2. Key Facts

Date	Planned: Olympic November 1945; Coronet March 1946; cancelled August 1945
Location	Kyushu and Honshu, Japan
Result	Never launched; cancelled after the atomic bombings and Japan’s surrender
Allied commanders	Gen. Douglas MacArthur (overall commander); Adm. Chester Nimitz (naval forces); Gen. George Marshall (Chief of Staff); Lt. Gen. Robert Eichelberger (Eighth Army); Lt. Gen. Courtney Hodges (First Army)
Japanese commanders	Field Marshal Shunroku Hata (Second General Army, Kyushu); Field Marshal Hajime Sugiyama (First General Army, Honshu); Adm. Soemu Toyoda (Navy)
Allied strength	Planned: more than 5 million men in total; Olympic: about 770,000 men; Coronet: about 1.5 million men
Japanese strength	About 2.3 million regular troops in Japan, plus about 4 million civilian militia; about 10,000 kamikaze aircraft
Estimated losses	American estimates for Olympic alone: 250,000 to more than 1,000,000 casualties; Japanese losses: millions (see Casualties section)

3. Background

The Road to Japan

By the summer of 1945, the Pacific War had reached the doorstep of Japan. The Americans had taken Iwo Jima in March 1945, at a cost of some 6,800 Marines killed, and Okinawa in June 1945, at a cost of some 12,000 Americans killed and more than 100,000 Japanese killed. The Japanese navy had been destroyed, the Japanese air force had been reduced to kamikaze attacks, and the American bombers, flying from the Marianas, were burning Japan’s cities to the ground. The firebombing of Tokyo on 9–10 March 1945 had killed some 100,000 people in a single night, and the bombings that followed had destroyed more than 60 Japanese cities. Japan was beaten, but it had not surrendered, and its leaders were preparing to fight on. The Americans, who had to decide how to end the war, had two options: to blockade and bomb Japan into surrender, or to invade it. The Joint Chiefs of Staff chose invasion, and the plan was codenamed Downfall.

Iwo Jima and Okinawa

The battles of Iwo Jima and Okinawa were the reason Downfall was expected to be so bloody, and they are the key to understanding the plan. At Iwo Jima, a tiny island of 8 square miles, the Marines lost some 6,800 men killed and 26,000 wounded, and the Japanese garrison of some 21,000 men was almost entirely killed. At Okinawa, a larger island, the Americans lost some 12,000 men killed and 38,000 wounded, and the Japanese lost more than 100,000 soldiers and some 100,000 civilians. The Japanese at Iwo Jima and Okinawa had fought to the death, from caves and tunnels, and they had inflicted casualties at a rate that shocked the Americans. The planners of Downfall looked at Iwo Jima and Okinawa and concluded that an invasion of Japan — a country of 70 million people, defended by millions of soldiers and civilians — would cost far more. The ratio of casualties at Okinawa, applied to Japan, produced estimates in the millions, and the planners did not shrink from them: they planned for the worst, and they expected the worst.

The Japanese Defence: Ketsu-Go

The Japanese plan for the defence of the home islands was codenamed Ketsu-Go — Operation Decisive — and it was a plan to make the invasion so costly that the Americans would negotiate a peace rather than demand unconditional surrender. The Japanese had about 2.3 million regular troops in Japan, organised into two General Armies: the First General Army, under Field Marshal Hajime Sugiyama, defending Honshu, and the Second General Army, under Field Marshal Shunroku Hata, defending Kyushu. Behind the regular army stood the civilian militia — the Volunteer Fighting Corps — some 4 million men and women, armed with bamboo spears, old rifles and grenades, and trained to fight and to die for the Emperor. The Japanese also had some 10,000 aircraft reserved for kamikaze attacks, to be used against the invasion fleet, and they had the remnants of the navy, including the battleship Yamato, which had been sunk in April 1945. The Japanese plan was to concentrate everything on Kyushu, where the Americans were expected to land first, and to destroy the invasion on the beaches.

The Kamikaze Threat

The kamikaze — the “divine wind” — was the most feared weapon in the Japanese arsenal, and it was the weapon the Americans feared most in Downfall. At Okinawa, the kamikaze had sunk 36 American ships and damaged more than 300, killing some 5,000 sailors, and the Japanese had learned that a single aircraft, flown into a ship, could do more damage than a squadron of bombers. For Downfall, the Japanese had reserved some 10,000 aircraft for kamikaze attacks, including trainers and obsolete planes, and they planned to use them in waves, against the invasion fleet, in the days before and during the landings. The Americans, who had studied the kamikaze at Okinawa, estimated that the attacks could sink or damage hundreds of ships and kill tens of thousands of men, before the first soldier had landed. The kamikaze was the reason the naval planners of Downfall were as worried as the army planners, and it was the reason the invasion fleet would have needed the largest air defence ever assembled.

4. Opposing Forces

The Allied Invasion Force

The Allied invasion force for Downfall was to be the largest ever assembled. Operation Olympic, the invasion of Kyushu in November 1945, was to involve about 770,000 men, in 14 divisions, landing on three beaches on the southern coast of Kyushu. The force was to be commanded by Lieutenant General Robert Eichelberger, of the Eighth Army, and it was to be supported by the Third Fleet, under Admiral William Halsey, and by the Far East Air Forces. Operation Coronet, the invasion of Honshu in March 1946, was to involve about 1.5 million men, in 25 divisions, landing on the Kanto Plain, near Tokyo, under Lieutenant General Courtney Hodges, of the First Army, transferred from Europe. The total force for Downfall was to number more than 5 million men, with more ships than the Normandy landings and more aircraft than any operation in history. The overall commander was General Douglas MacArthur, the Supreme Commander for the Allied Powers, who had commanded the Pacific War from Australia and the Philippines.

MacArthur and Nimitz

The command of Downfall was divided between two men who did not always agree: General Douglas MacArthur, who commanded the army forces, and Admiral Chester Nimitz, who commanded the naval forces. MacArthur, who had returned to the Philippines in 1944 and had commanded the liberation of the islands, believed that the invasion of Japan was necessary and that it could be done. Nimitz, who had commanded the naval war in the Pacific, believed that the blockade and the bombing would bring Japan to surrender without an invasion, and he was sceptical of the need for Downfall. The disagreement was resolved by the Joint Chiefs of Staff, who ordered the invasion, and by the atomic bomb, which made it unnecessary. MacArthur, who would have commanded the invasion, instead commanded the occupation of Japan, and he did so with a skill that surprised even his critics. Nimitz, who had doubted the invasion, was proved right in a way he had not expected: the bomb, not the blockade, ended the war.

The Japanese Defenders

The Japanese forces in the home islands numbered about 2.3 million regular troops, organised into two General Armies and a large number of divisions, many of them newly raised and poorly equipped. The First General Army, under Field Marshal Hajime Sugiyama, defended Honshu, the main island, with about 1.5 million men. The Second General Army, under Field Marshal Shunroku Hata, defended Kyushu, with about 800,000 men. Behind the regular army stood the Volunteer Fighting Corps, some 4 million civilians, armed with bamboo spears, old rifles and grenades, and trained to fight to the death. The Japanese also had some 10,000 aircraft, most of them reserved for kamikaze attacks, and the remnants of the navy, including submarines and midget submarines. The Japanese forces were large in number but weak in quality: their divisions were understrength, their equipment was poor, and their air force had been reduced to suicide attacks. But they were fighting for their homes, and they were prepared to die.

The Volunteer Fighting Corps

The Volunteer Fighting Corps was the most extraordinary part of the Japanese defence, and it is the measure of how far Japan was prepared to go. The Corps was a militia of some 4 million men and women, aged 15 to 60, armed with bamboo spears, old rifles, grenades and Molotov cocktails, and trained to fight the invaders in the streets, in the fields and in the mountains. The Corps was not a military force in the ordinary sense: its members had little training, no uniforms and no heavy weapons, and they would have been slaughtered by the American army. But their existence was a statement: Japan would not surrender, and its people would die rather than submit. The Americans, who knew about the Corps from their intelligence, understood what it meant: the invasion of Japan would not be a battle against an army but a battle against a nation, and the casualties — on both sides — would be counted in the millions.

	Allies	Japan
Army	Olympic: about 770,000 men, 14 divisions; Coronet: about 1.5 million men, 25 divisions	About 2.3 million regular troops; about 4 million civilian militia
Navy	Third and Fifth Fleets; more ships than Normandy	Remnants: submarines, midget submarines; Yamato sunk April 1945
Air force	Far East Air Forces; carrier aircraft	About 10,000 aircraft, mostly for kamikaze attacks
Kamikaze	—	About 10,000 aircraft reserved for suicide attacks
Command	MacArthur (overall); Nimitz (naval); Eichelberger (Olympic); Hodges (Coronet)	Hata (Kyushu); Sugiyama (Honshu); Toyoda (Navy)

5. The Battle

Operation Olympic: The Invasion of Kyushu

Operation Olympic was to be the first invasion, and it was to be launched on 1 November 1945, against the southern island of Kyushu. The plan called for 14 divisions — about 770,000 men — to land on three beaches on the southern coast of Kyushu: at Miyazaki, at Ariake Bay and at Kushikino. The landings were to be preceded by a naval bombardment and by air attacks, and they were to be supported by the Third Fleet, under Halsey, and by the Far East Air Forces. The objective was to seize the southern third of Kyushu, to build airfields from which the bombers could support Coronet, and to establish a base for the invasion of Honshu. The Japanese, who had correctly guessed that Kyushu would be the first target, had concentrated their forces there: the Second General Army, under Hata, had some 800,000 men on the island, and the kamikaze aircraft were ready. The battle for Kyushu would have been the bloodiest of the war, and it never happened.

The Three Beaches

The three landing beaches for Olympic were chosen for their suitability for an amphibious assault, and they were the beaches the Japanese defended most heavily. Miyazaki, on the eastern coast of Kyushu, was a long, flat beach, ideal for a landing, and it was defended by the Japanese 57th Army. Ariake Bay, on the southern coast, was a sheltered bay, ideal for the landing craft, and it was defended by the Japanese 40th Army. Kushikino, on the western coast, was a smaller beach, to be used for a subsidiary landing, and it was defended by local forces. The Americans, who had studied the beaches from aerial photographs, knew they were defended, and they planned to land in strength, with tanks, artillery and air support. The Japanese, who had studied the same beaches, knew where the Americans would land, and they planned to meet them on the beaches, with everything they had. The three beaches were the places where the bloodiest battle of the war would have been fought, and they are quiet now, places of fishermen and holidaymakers.

Operation Coronet: The Invasion of Honshu

Operation Coronet was to be the second invasion, and it was to be launched on 1 March 1946, against the main island of Honshu. The plan called for 25 divisions — about 1.5 million men — to land on the Kanto Plain, near Tokyo, in the largest amphibious operation in history. The force was to be commanded by Lieutenant General Courtney Hodges, of the First Army, transferred from Europe, and it was to be supported by the Fifth Fleet and by the air forces that had been built up on Kyushu after Olympic. The objective was to take Tokyo, to destroy the Japanese government, and to end the war. The Japanese, who had concentrated their forces on Kyushu, would have had four months to reinforce Honshu, and the First General Army, under Sugiyama, had some 1.5 million men on the island. The battle for Honshu would have been larger than Olympic, and bloodier, and it never happened.

The Kanto Plain

The Kanto Plain, the landing area for Coronet, is the largest plain in Japan, and it is the heart of the country. The plain is a flat, open area around Tokyo Bay, and it is the most densely populated part of Japan, with millions of people living in Tokyo, Yokohama and the surrounding cities. The Americans chose the Kanto Plain because it was flat, because it was close to Tokyo, and because it was the place where a landing could be made in strength. The Japanese chose to defend it because it was the heart of Japan, and because the loss of Tokyo would mean the loss of the war. The battle for the Kanto Plain would have been fought in the streets of the greatest cities of Japan, and it would have been a battle of millions, fought house by house, street by street. The plain is quiet now, a place of cities and suburbs, and the battle that would have been fought there is a battle that never was.

The Atomic Bombs and the Surrender

The invasion was cancelled in August 1945, by events that the planners had not foreseen. On 6 August 1945, the atomic bomb was dropped on Hiroshima, killing some 140,000 people by the end of the year. On 9 August, a second atomic bomb was dropped on Nagasaki, killing some 70,000 people. On 8 August, the Soviet Union declared war on Japan and invaded Manchuria, destroying the Japanese Kwantung Army in a matter of days. On 14 August, the Japanese government, faced with the atomic bombs and the Soviet invasion, accepted the Allied demand for unconditional surrender, and on 15 August, the Emperor announced the surrender in a radio broadcast. The formal surrender was signed on 2 September 1945, aboard the battleship USS Missouri in Tokyo Bay. Operation Downfall, which had been planned for November 1945 and March 1946, was cancelled, and the invasion fleet, which had been assembled, was dispersed. The war was over, and the invasion that would have been the bloodiest campaign in American history never happened.

Hiroshima, Nagasaki and Manchuria

The three events of August 1945 — Hiroshima, Nagasaki and the Soviet invasion of Manchuria — together ended the war, and historians have debated ever since which of them mattered most. The atomic bombs, which killed about 210,000 people, shocked the Japanese leadership and convinced the Emperor that the war could not be won. The Soviet invasion, which destroyed the Kwantung Army and removed Japan’s last hope of a negotiated peace through Moscow, convinced the Japanese government that there was no way out. The two together — the bombs and the invasion — made surrender inevitable, and the Japanese government, which had been divided between those who wanted to fight on and those who wanted to surrender, chose surrender. The debate about which event mattered more is still unresolved, and it is a debate that goes to the heart of the question of whether the atomic bombs were necessary, and whether Downfall would have been necessary without them.

6. Turning Point

The Casualty Estimates

The turning point of Downfall was not a battle but a number: the casualty estimates. The planners of the invasion, who had studied Iwo Jima and Okinawa, estimated that Olympic alone would cost the Americans from 250,000 to more than 1,000,000 casualties, and that Coronet would cost more. The estimates were based on the ratio of casualties at Okinawa, where the Americans had lost 12,000 killed for an island of 100,000 defenders, applied to Japan, where the defenders numbered in the millions. The estimates were so high that they shocked the American leadership, and they were the reason the atomic bomb was seen, by many, as the lesser evil. The casualty estimates were the turning point because they made the invasion seem too costly to attempt, and they made the bomb seem necessary. The estimates have been debated ever since, and some historians have argued that they were exaggerated, but they were the numbers the planners worked with, and they were the numbers that decided the war.

A Million Casualties?

The highest estimates for Downfall — more than a million American casualties — have been the most debated numbers of the operation, and they deserve careful attention. The estimates were made by different people, at different times, using different methods, and they varied widely: the Joint Chiefs of Staff estimated 250,000 casualties for Olympic, the Army estimated 500,000, and some planners, using the Okinawa ratio, estimated more than a million. The highest estimates were based on the assumption that the Japanese would fight to the death, as they had at Iwo Jima and Okinawa, and that the invasion would be a battle of annihilation. The lowest estimates were based on the assumption that the Japanese would collapse, as the Germans had in 1945, and that the invasion would be a pursuit rather than a battle. The truth, which we will never know, is probably somewhere in between, but the estimates, whatever their accuracy, were the numbers that the American leadership saw, and they were the numbers that made the bomb seem necessary.

The Decision to Use the Bomb

The second turning point was the decision to use the atomic bomb, and it was a decision that was made, in part, because of Downfall. President Harry Truman, who had become president in April 1945, after the death of Franklin Roosevelt, was told about the casualty estimates for Downfall, and he was told that the atomic bomb could end the war without an invasion. Truman, who had never wanted to invade Japan, and who had been horrified by the casualties at Okinawa, authorised the use of the bomb, and the bombs were dropped on Hiroshima and Nagasaki. The decision has been debated ever since, and it is one of the most contested decisions in history. Truman’s defenders have said that the bomb saved lives — American and Japanese — by making the invasion unnecessary. Truman’s critics have said that Japan would have surrendered without the bomb, and that the bomb was unnecessary and immoral. The debate is, at its heart, a debate about Downfall, and about whether the invasion would have cost more lives than the bomb did.

Truman’s Choice

Truman’s choice was made in the summer of 1945, in the shadow of Okinawa and in the light of the casualty estimates for Downfall. Truman was a new president, who had not been told about the atomic bomb until he took office, and he was faced with a decision that no president had ever faced: whether to use a weapon that could destroy a city in a single blast. He was advised by his generals, who told him the invasion would cost hundreds of thousands of lives, and by his scientists, who told him the bomb would work. He chose the bomb, and he chose it because he believed it would save lives — American lives, and, in the long run, Japanese lives as well. Whether he was right is a question that historians will debate forever, but his choice was made in the context of Downfall, and it cannot be understood without Downfall. The bomb and the invasion are two sides of the same decision, and the decision was Truman’s.

7. Casualties and Losses

The Estimates: What Downfall Would Have Cost

Downfall was never fought, so there are no actual casualties to count — only estimates, and the estimates vary widely. For Operation Olympic alone, American estimates ranged from 250,000 to more than 1,000,000 casualties, with the Joint Chiefs of Staff estimating 250,000, the Army estimating 500,000, and some planners, using the Okinawa ratio, estimating more than a million. For Coronet, the estimates were higher still, and the total for Downfall was estimated in the millions. The Japanese losses, military and civilian, were estimated in the millions as well: the Japanese army would have lost hundreds of thousands of men, and the civilian population, caught in the fighting and in the bombing, would have lost millions. The estimates are the measure of what Downfall would have cost, and they are the reason the operation is remembered as the bloodiest campaign that never happened.

The Okinawa Ratio

The casualty estimates for Downfall were based, in large part, on the ratio of casualties at Okinawa, and the ratio is worth understanding. At Okinawa, the Americans lost some 12,000 men killed and 38,000 wounded, for an island defended by some 100,000 Japanese soldiers. The ratio — about one American casualty for every two Japanese defenders — was applied to Japan, where the defenders numbered in the millions, and the result was estimates in the millions. The ratio was crude, and it has been criticised: Okinawa was an island, Japan is a country; the Japanese at Okinawa fought from caves, the Japanese in Japan would have fought in cities; and the Americans at Okinawa did not have the atomic bomb. But the ratio was the best estimate the planners had, and it was the estimate that shocked the American leadership into considering the bomb. The Okinawa ratio was the arithmetic of Downfall, and it was the arithmetic that ended the war.

The Bombs: The Actual Cost

The actual cost of ending the war without Downfall was the cost of the atomic bombs: some 140,000 people killed at Hiroshima by the end of 1945, and some 70,000 at Nagasaki, for a total of about 210,000 dead, with many more injured and with the survivors suffering from radiation sickness for the rest of their lives. The firebombing of Japan’s cities, which had already killed hundreds of thousands of people, continued until the surrender, and the total Japanese civilian death toll from bombing was more than 500,000. The Soviet invasion of Manchuria killed tens of thousands more. The cost of ending the war without an invasion was terrible, and it is the cost against which Downfall is judged: the bombs killed about 210,000 people, and the invasion would have killed millions. Whether the comparison justifies the bombs is a question that has been debated ever since, and it is a question that has no easy answer.

Hiroshima and Nagasaki

The atomic bombings of Hiroshima and Nagasaki are the most controversial events of the Second World War, and they are remembered as such. Hiroshima, on 6 August 1945, was a city of some 340,000 people, and the bomb — “Little Boy”, a uranium bomb — killed some 140,000 people by the end of the year, through the blast, the fire and the radiation. Nagasaki, on 9 August 1945, was a city of some 250,000 people, and the bomb — “Fat Man”, a plutonium bomb — killed some 70,000 people. The survivors — the hibakusha — suffered from radiation sickness, from cancers and from burns, for the rest of their lives, and their children suffered too. The bombings are remembered in Japan as a national trauma, and in the United States as a terrible necessity, and the debate about them is the debate about Downfall: about whether the invasion would have cost more, and about whether Japan would have surrendered without them.

	Estimated for Downfall	Actual cost of the bombs
American casualties	250,000 to more than 1,000,000 (Olympic alone)	None from the bombs
Japanese military losses	Hundreds of thousands	—
Japanese civilian losses	Millions	Hiroshima: about 140,000; Nagasaki: about 70,000
Total	Millions	About 210,000 from the two bombs

8. Map and Geography

The Home Islands of Japan

Japan is an archipelago of four main islands — Hokkaido, Honshu, Shikoku and Kyushu — and its geography shaped Downfall as much as any decision by the generals. The islands are mountainous, with narrow coastal plains, and the population is concentrated in the cities on the plains. Kyushu, the southernmost of the main islands, is a mountainous island with a long coastline, and its southern coast — where Olympic was to land — is a flat, open shore, ideal for an amphibious assault. Honshu, the largest island, is dominated by the Kanto Plain, around Tokyo Bay, and the plain is the heart of Japan, with millions of people living in Tokyo, Yokohama and the surrounding cities. The geography of Japan — mountains, plains and a long coastline — meant that the invasion would have to be fought on the plains, in the cities, and the Japanese, who knew the ground, would have defended it street by street.

Kyushu and Honshu

Kyushu and Honshu were the two targets of Downfall, and they were chosen for different reasons. Kyushu was chosen for Olympic because it was the closest to the American bases in Okinawa, because its southern coast was suitable for a landing, and because it could provide the airfields from which the bombers could support Coronet. Honshu was chosen for Coronet because it was the heart of Japan, because Tokyo was there, and because the capture of Tokyo would end the war. The two islands are separated by the Kanmon Strait, a narrow passage of water, and the Japanese, who controlled the strait, could move forces between the islands. The geography of the two islands — Kyushu in the south, Honshu in the north, with the strait between them — meant that the invasion would have to be fought in two stages, with a gap of four months between them, and the Japanese would have had time to reinforce Honshu while the Americans were fighting on Kyushu.

The Kanto Plain and Tokyo Bay

The Kanto Plain and Tokyo Bay were the objective of Coronet, and they were the heart of Japan. The plain is a flat, open area, some 100 kilometres across, around Tokyo Bay, and it is the most densely populated part of Japan, with more than 20 million people living in the Tokyo-Yokohama area today. In 1945, the plain was the home of the Japanese government, the Imperial Palace, the military headquarters and the industries that made Japan’s weapons. The Americans chose the Kanto Plain because it was flat, because it was close to Tokyo, and because a landing there could be made in strength. The Japanese chose to defend it because it was the heart of Japan, and because its loss would mean the loss of the war. The battle for the Kanto Plain would have been the largest land battle in the Pacific War, and it never happened.

Tokyo: The Ultimate Objective

Tokyo was the ultimate objective of Downfall, and it was the city the Americans would have had to take to end the war. Tokyo in 1945 was a city of some 3 million people — reduced from 7 million by the evacuations and the bombings — and it was the seat of the Emperor, the government and the military. The city had already been devastated by the firebombing of March 1945, which had killed some 100,000 people and destroyed a quarter of the city, but it was still the capital, and its capture would have been the end of the Japanese government. The battle for Tokyo would have been fought street by street, house by house, and it would have cost hundreds of thousands of lives, on both sides. The city is quiet now, a place of millions of people and of neon lights, and the battle that would have been fought there is a battle that never was.

9. Outcome and Legacy of Operation Downfall

The Occupation of Japan

The cancellation of Downfall led directly to the occupation of Japan, which began on 28 August 1945, when the first American troops landed at Atsugi airfield, near Tokyo. The occupation, under General Douglas MacArthur, lasted until 1952, and it transformed Japan from a militarist empire into a democratic, peaceful country. MacArthur, who would have commanded the invasion, instead commanded the occupation, and he did so with a skill that surprised even his critics: he preserved the Emperor, he wrote a new constitution, he reformed the land and the economy, and he laid the foundations for the Japan of today. The occupation was the alternative to the invasion, and it was the alternative that worked: Japan, which would have been destroyed by Downfall, was rebuilt by the occupation, and it became one of the most successful countries in the world.

MacArthur’s Japan

MacArthur’s occupation of Japan is remembered as one of the most successful occupations in history, and it is the legacy of Downfall’s cancellation. MacArthur, who had been the commander of the invasion that never happened, became the Supreme Commander for the Allied Powers, and he ruled Japan for seven years, with a power that no foreigner had ever held over the country. He preserved the Emperor, Hirohito, as a symbol of continuity, he disbanded the military, he wrote a constitution that renounced war, and he reformed the economy and the society. The Japan that emerged from the occupation was a democracy, an ally of the United States, and an economic miracle. The occupation was the peace that Downfall would have made impossible, and it was the peace that the atomic bombs, for all their horror, made possible. The Japan that MacArthur governed became the Japan of the post-war world, and the occupation he led is still studied as the most successful military occupation in history, and the most humane.

The Debate About the Bomb

The legacy of Downfall is the debate about the atomic bomb, and the debate has never ended. The bomb’s defenders have said that it saved lives, by making Downfall unnecessary, and that the invasion would have cost millions of lives, American and Japanese. The bomb’s critics have said that Japan would have surrendered without the bomb, that the Soviet invasion of Manchuria was enough, and that the bomb was a war crime. The debate is, at its heart, a debate about Downfall: about the casualty estimates, about the Japanese will to fight, and about whether the invasion would have been necessary. The historians who have studied the Japanese records have found that the Japanese government was divided, that the Emperor wanted peace, and that the military wanted to fight on — and that the bombs, and the Soviet invasion, together tipped the balance. The debate will continue, because it is a debate about the most terrible decision of the war, and about the invasion that never happened.

The Invasion That Never Was

Downfall is remembered as the invasion that never was, and its memory is kept alive by the debate about it. The plan is studied in military academies, the casualty estimates are debated by historians, and the beaches of Kyushu — Miyazaki, Ariake Bay and Kushikino — are visited by those who wonder what would have happened there. The invasion that never happened is a reminder of what the war would have cost if it had gone on, and of what the atomic bomb — for all its horror — prevented. The men who would have fought Downfall — the Americans who would have landed on Kyushu, and the Japanese who would have defended it — are grateful, in their different ways, that it never happened, and their gratitude is the most human legacy of the operation. Downfall was the largest operation ever planned, and its cancellation was the end of the Second World War.

10. Commanders

The Allied Commanders

General Douglas MacArthur (United States). Supreme Commander for the Allied Powers and the overall commander of Operation Downfall. MacArthur had commanded the Pacific War from Australia and the Philippines, and he would have commanded the invasion of Japan. Instead, he commanded the occupation of Japan, from 1945 to 1951, and he transformed the country. MacArthur is remembered as one of the great American generals, and as the man who, having planned the largest invasion in history, presided over the most successful occupation in history.

Admiral Chester Nimitz (United States). Commander of the Pacific Fleet and the naval commander for Downfall. Nimitz had won the Battle of Midway and had commanded the naval war in the Pacific, and he believed that the blockade and the bombing would bring Japan to surrender without an invasion. He was proved right, in a way he had not expected, by the atomic bomb. Nimitz signed the Japanese surrender aboard the USS Missouri on 2 September 1945, as the representative of the United States Navy.

General George Marshall (United States). Chief of Staff of the United States Army and the man who, with the Joint Chiefs of Staff, ordered the invasion. Marshall was the architect of the American war effort, and he was the man who had to decide whether to invade Japan. He supported the invasion, and he supported the use of the atomic bomb, and his decisions shaped the end of the war. Marshall later served as Secretary of State, and he is remembered for the Marshall Plan, which rebuilt Europe.

MacArthur: From Invasion to Occupation

MacArthur’s career is defined by the contrast between the invasion he planned and the occupation he carried out. The invasion of Japan would have been the largest operation in history, and it would have cost millions of lives. The occupation of Japan was the most successful occupation in history, and it cost almost no lives. MacArthur, who had planned the one, carried out the other, and he did so with a skill that surprised even his critics. He preserved the Emperor, he wrote a constitution, he reformed the country, and he laid the foundations for the Japan of today. MacArthur’s Japan is the legacy of Downfall’s cancellation, and it is the reason the invasion that never happened is remembered as a blessing, not as a missed opportunity. The general who would have invaded Japan became the general who rebuilt it, and the two roles are the two sides of his career.

The Japanese Commanders

Field Marshal Shunroku Hata (Japan). Commander of the Second General Army, defending Kyushu, where the Americans were expected to land first. Hata was a veteran of the war in China and one of Japan’s most capable generals. He concentrated his forces on Kyushu, prepared to destroy the invasion on the beaches, and waited for an invasion that never came. After the surrender, he was tried for war crimes and sentenced to life imprisonment, and he was released in 1954. He died in 1962.

Field Marshal Hajime Sugiyama (Japan). Commander of the First General Army, defending Honshu, and the former Chief of the General Staff. Sugiyama was one of the architects of Japan’s war, and he was a leading advocate of fighting to the death. On the day of the surrender, 15 August 1945, he shot himself, rather than live to see Japan defeated. His death was the end of the old Japan, and the beginning of the new.

Admiral Soemu Toyoda (Japan). Commander-in-Chief of the Japanese Navy and the man responsible for the kamikaze attacks. Toyoda, who had commanded the Combined Fleet, organised the kamikaze forces for the defence of the home islands, and he planned to use them against the invasion fleet. After the surrender, he was tried for war crimes and acquitted. He died in 1957.

Hata: The Defender of Kyushu

Hata’s defence of Kyushu was the most important part of the Japanese plan, and it was the part that would have decided the battle. Hata, who had correctly guessed that the Americans would land on Kyushu first, concentrated his forces there: some 800,000 men, with tanks, artillery and the kamikaze aircraft, ready to meet the invasion on the beaches. His plan was to destroy the invasion in the first days, before the Americans could establish a beachhead, and to make the cost so high that the Americans would negotiate. The plan was never tested, because the invasion never came, but Hata’s preparations were real, and they were the reason the American planners estimated such high casualties for Olympic. Hata waited for the invasion, and when it did not come, he surrendered with his army, and he spent the rest of his life in prison and in obscurity. His defence of Kyushu is remembered as the defence that never was, and as the measure of what the invasion would have cost.

Frequently Asked Questions

What was Operation Downfall?
The Allied plan to invade Japan in 1945–46: Operation Olympic, the invasion of Kyushu in November 1945, and Operation Coronet, the invasion of Honshu in March 1946. The plan was cancelled in August 1945, after the atomic bombings and Japan’s surrender.

How many men would have taken part in Operation Downfall?
More than 5 million Allied soldiers, sailors and airmen in total: about 770,000 men in Olympic, and about 1.5 million men in Coronet, with millions more in support. The Japanese had about 2.3 million regular troops and about 4 million civilian militia.

How many casualties were expected in Operation Downfall?
American estimates for Olympic alone ranged from 250,000 to more than 1,000,000 casualties, and the total for Downfall was estimated in the millions. Japanese losses, military and civilian, were also estimated in the millions. The estimates are debated, and some historians believe they were exaggerated.

Why was Operation Downfall cancelled?
Because Japan surrendered in August 1945, after the atomic bombings of Hiroshima (6 August) and Nagasaki (9 August) and the Soviet invasion of Manchuria (8 August). The formal surrender was signed on 2 September 1945.

Did the atomic bombs make Operation Downfall unnecessary?
That is the central debate. The bomb’s defenders say it saved lives by making the invasion unnecessary. The bomb’s critics say Japan would have surrendered without the bomb, and that the Soviet invasion of Manchuria was enough. Historians continue to debate the question.

What is Ketsu-Go?
The Japanese plan for the defence of the home islands — Operation Decisive — under which the Japanese would concentrate everything on Kyushu, use some 10,000 kamikaze aircraft against the invasion fleet, and fight to the death, with the army and with 4 million civilian militia, to make the invasion so costly that the Americans would negotiate.

Sources

1. Wikipedia, “Operation Downfall” — dates, the plan, the forces, the casualty estimates and the cancellation.
2. Richard B. Frank, Downfall: The End of the Imperial Japanese Empire (Random House, 1999) — the most detailed history of Downfall, the casualty estimates and the decision to use the bomb.
3. Encyclopædia Britannica, “Operation Downfall” — background, the plan and its outcome.
4. John Ray Skates, The Invasion of Japan: Alternative to the Bomb (University of South Carolina Press, 1994) — the plan for Olympic and Coronet, the Japanese defences and the estimates.
5. D. M. Giangreco, Hell to Pay: Operation Downfall and the Invasion of Japan, 1945–1947 (Naval Institute Press, 2009) — the casualty estimates, the Japanese defences and the debate about the bomb.
6. Tsuyoshi Hasegawa, Racing the Enemy: Stalin, Truman, and the Surrender of Japan (Harvard University Press, 2005) — the Soviet invasion of Manchuria and its role in Japan’s surrender.

Further reading

• Robert S. Norris, Racing for the Bomb: General Leslie R. Groves, the Manhattan Project’s Indispensable Man (Steerforth, 2002).
• Herbert P. Bix, Hirohito and the Making of Modern Japan (HarperCollins, 2000).