The Question of Japanese Surrender

Following the March fire raids and the U.S. invasion of Okinawa in early April, the Japanese government finally showed signs of movement toward peace. When the Soviet Union renounced its neutrality pact with Japan on April 5, suggesting that it would join the United States against Japan after Germany was defeated, General Koiso became convinced that he had failed the emperor and resigned as premier. Kantaro Suzuki, a former admiral in the Imperial Navy, took Koiso’s place. Suzuki set up a small inner war council of six, including himself, the foreign minister, the navy minister, the war minister, and the two military chiefs of staff. Of these, the first three leaned toward peace. 

The death of President Roosevelt as a result of a stroke on April 12 and the surrender of Germany on May 7 had some effect on the Imperial government. Japanese officials representing the peace party approached the Soviets to seek continued Russian neutrality and to see if the Soviet Union might serve as a mediator with the Allies. The Soviets refused. They were preparing to invade Japanese-held territory in Asia and knew that the new U.S. president, Harry S Truman, pursued the same policy as his predecessor in seeking an unconditional Japanese surrender. 

By July 1945, Japan was reeling from the effects of the U.S. naval blockade and air offensive. Food shortages were so severe that the government urged people to collect acorns. Incendiary attacks from the air had destroyed 2.5 million houses, leaving millions of people homeless. Aware of Japan’s distress, both Arnold and LeMay believed that the enemy might surrender without an invasion. General Marshall did not share their opinion. He believed the Japanese would continue to resist the pressure of air and sea power. Marshall told Truman that bombing and blockade alone had not defeated Germany and likely would not defeat Japan either. At President Truman’s direction, the Joint Chiefs of Staff continued to prepare for the invasion of Japan.

Invasion plans required about five million Allied troops, most of them from the United States. In the first stage, Operation Olympic, Allied forces would invade Kyushu in November 1945. In the second stage, Operation Coronet, scheduled for March 1946, the invasion troops would assault Honshu. U.S. planners had no illusions about the costs of the invasions. The Japanese had gathered more than 8,000 airplanes to use as kamikazes against the invasion fleet. About two million Japanese troops, supported by twenty-eight million armed civilians, awaited the invaders. If the U.S. casualty rate for the invasion of Kyushu matched the 35 percent casualty rate experienced on Okinawa, 268,000 Americans might be killed or wounded during Operation Olympic alone. Experts estimated that the entire invasion of Japan, including the assault on Honshu, would kill or wound a million Americans, and many more Japanese. An alternative to the invasion might save lives, and that alternative was waiting in the wings.