Today is the 70th anniversary of the bombing of Hiroshima. We are already seeing the usual retrospectives about the ending of the war with Japan, and whether the use of the atomic bomb was necessary. Let’s consider a surprising counterfactual: If the A-bombs had not been dropped and had Japan not surrendered in August 1945, the US might not have gone through with the planned invasion of the Japanese homeland.
On June 18, 1945 at a White House meeting with the Joint Chiefs of Staff, the Secretary of War, and the Secretaries of the Army and Navy, President Harry Truman approved plans for the invasion of Japan. The key participants were the President, General George C. Marshall, and Admiral Ernest King. In 1999, using documents that had only been declassified in the past decade, Richard B. Frank published Downfall: The End of the Imperial Japanese Empire. It reshaped our understanding of the final months of the Second World War and the endgame that culminated with the Japanese surrender on August 14, 1945. (The formal ceremony took place on the USS Missouri, in Tokyo Bay, on September 2.)
What were Truman and the others thinking as they walked into that meeting room on June 18? The night before, Truman wrote in his diary that the decision to “invade Japan [or] bomb and blockade” would be his “hardest decision to date.” The men entering the meeting knew the American public was increasingly war-weary, shocked by the enormous casualties of the past year. In the first 30 months of the war, the U.S. suffered 91,000 battle deaths, about 3,000 a month. In June 1944, the toll accelerated with the D-Day landings and the assault on Saipan in the Pacific. In the next twelve months, 196,000 Americans died in combat, an average of more than 16,000 a month. The European war had ended in May, and public pressure to bring the troops home was increasing.
As we approached Japan in early 1945, the war in the Pacific was growing even bloodier. During five weeks in February and March, 1945, 7,000 Americans died and 17,000 were wounded fighting 21,000 Japanese soldiers on the eight square miles of Iwo Jima. At the dedication of the 3d Marine Division Cemetery on Iwo, Major General Graves B. Erskine described the desperation of the fight:
Victory was never in doubt. Its cost was. The enemy could have displaced every cubic inch of volcanic ash on this fortress with concrete pillboxes and blockhouses, which he nearly did, and still victory would not have been in doubt.
What was in doubt, in all our minds, was whether there would be any of us left to dedicate our cemetery at the end, or whether the last Marine would die knocking out the last Japanese gun and gunner.
Iwo Jima was followed, on April 1, by the landing on Okinawa. Over the next ten weeks, another 50,000 American soldiers and sailors were killed or wounded while eliminating a Japanese garrison of 92,000. The struggle came to resemble the trench warfare of the First World War, and was likewise so grinding and unrelenting as to result in thousands of additional psychiatric casualties.
They knew that the Allied policy was unconditional surrender for Japan, as set by FDR and Churchill at the Casablanca Conference in 1943.
They knew that the Magic Summaries showed no Japanese government disposition for peace on these terms.
They knew that Japan still had two million military personnel stationed outside Japan from New Guinea to the Dutch East Indies, the Philippines, China, Korea, Burma and Indochina; and they wanted to force a formal surrender by the Japanese government to avoid years of piecemeal fighting with all of these isolated forces.
By the end of the June 18 meeting, Truman, his generals, and cabinet had decided on a broad strategy for the invasion of Japan. The first landings would be on the southernmost of the four main Japanese homeland islands, Kyushu, on November 1, 1945. The seizure of Kyushu would allow the Air Force to build airfields for the fighter aircraft that would provide cover for the landing on the Honshu plain near Tokyo, on March 1 of the following year.
Truman was told that military planners assumed about 760,000 American troops would face 350,000 Japanese on Kyushu, supported by about 2,500-3,000 aircraft. Although the Joint Chiefs unanimously supported his decision, Truman was not told that the Navy — unlike the Army — did not believe an invasion would ultimately be needed, or that in Admiral King’s view, he was only supporting preparations for the landing on Kyushu. King believed a blockade and aerial bombing would force Japan’s surrender.
Six weeks later, American intelligence had assembled a completely different picture about what awaited us on Kyushu. The Japanese Army had figured out the American landing would be on the island, and bet everything on a strategy of inflicting maximum casualties to achieve a negotiated settlement to the war, one that would preserve the Emperor, prevent the Allied occupation of Japan, and allow Japan to retain portions of its overseas empire. What changed in those few weeks?
- Instead of 350,000 Japanese troops, American intelligence now estimated there would be 650,000. (It was discovered after the war that the Japanese had in fact packed 900,000 troops onto the island);
- Instead of 2,500-3,000 aircraft, the Japanese had between 6,000 and 10,000, and were planning to employ them in waves of kamikaze attacks against vulnerable transport ships as they approached landing beaches packed with thousands of American troops. (The Okinawa kamikaze attacks had been on warships);
- The entire civilian population of the island had been mobilized, armed (in some cases just with hoes and spades), and trained to attack the American soldiers when they came ashore, leaving the U.S. military unable to distinguish between soldiers and civilians, and resulting in enormous casualties on both sides;
- The Japanese military had issued orders to kill all Allied prisoners of war once the American invasion began.
During these weeks, the Magic Diplomatic Summaries indicated no improved prospects of a peace offer from Japan on Allied terms. An enormous literature on this topic has been accrued in the past half-century; suffice to say, Japan’s foreign minister admitted, after the war, that the Japanese cabinet never agreed on a plan for terminating the war. The Magic intercepts revealed a series of communications between the government and its ambassadors that were confusing in many respects, but always clear on one: unconditional surrender was unacceptable, and events such as casualties inflicted on Americans during the anticipated invasion might lead to the termination of the war on more favorable terms.
For those who wish to read more about the rise and fall of the revisionist viewpoint that blames America for the war’s continuation, Michael Kort’s The Historiography of Hiroshima: The Rise and Fall of Revisionism is an excellent start.
According to Frank, the new intelligence probably would have led Admiral King to withdraw his support for the Kyushu landing. Had the war not ended by the second half of August, he believes, this would have prompted President Truman to undertake a new strategic review. Meanwhile, the United States Army Air Forces had come up with a new approach to strategic bombing, which it planned to implement in September 1945. Unlike the massive incendiary attacks that burned down large parts of Japan’s biggest cities between March and June, the new campaign focused on a small number of key rail yards, bridges, tunnels, and ferries. The Air Force had realized that with Japan’s poor road network (mostly still unpaved), the distribution of food supplies could be paralyzed by disrupting fewer than 100 rail and shipping locations. With Japan’s population already on the brink of starvation, the effect of this campaign would have been catastrophic.
This strategic review would have provoked intense controversy within the Administration, since the Army was still committed to the invasion strategy. There is no indication that Truman ever knew of the new intelligence on the Japanese military buildup on Kyushu or of the new bombing plan; and with the end of the war, it was not necessary to raise the issue to the Presidential level. All of this creates a hypothetical future where no American invasion of Japan would have happened, even if the war had gone on beyond mid-August. The likely results:
- Continued American blockade of the Japanese home islands and complete disruption of the food supply by the Air Force bombing campaign, causing starvation in the civilian population;
- The Soviet invasion of Hokkaido — the northernmost home island of Japan, then lightly-defended — in September 1945. This was one of the revelations from the opening of the Soviet archives in the 1990s;
- The British invasion of Malaya in early September, which would have caused heavy casualties against the Japanese forces anticipating the operation;
- Continued fighting in the Philippines, on smaller islands across the Pacific, and in China;
- Huge death tolls of Asian civilians under Japanese occupation (primarily in China and secondarily in Southeast Asia), estimated at 100,000 to 250,000 a month from famine, disease, imprisonment, and execution.
How long could Japan have survived in this scenario? Would the ending have been an organized surrender of all Japanese military forces, or a disorganized collapse with scattered fighting continuing across the Pacific and mainland Asia? The end of the Pacific war, like the end of the European war, would have been grim under any scenario.
To learn more about these events, you can read my original post, at Things Have Changed. For those interested in the complicated history and the methodology used in the invasion casualty estimates, read D.M. Giangreco’s “A Score of Bloody Okinawas and Iwo Jimas” in Hiroshima In History, edited by Robert James Maddox (2007).