The Last Days of Imperial Japan

U.S. forces battle Japanese troops for control of the strategic island of Iwo Jima. The U.S. mission, Operation Detachment, is the amphibious invasion [PDF] of the island after months of aerial and naval shelling. The battle is one of the bloodiest in Marine Corps history, killing nearly seven thousand U.S. Marines and more than twenty thousand Japanese soldiers in the thirty-six days of fighting. The island later serves as an emergency landing site for U.S. B-29 bombers.

The United States launches an extensive air campaign, dropping more than two thousand tons of incendiary explosives on Tokyo over two days. The bombardment leaves Tokyo in ruins, destroying nearly sixteen square miles. An estimated eighty thousand to one hundred thousand civilians die. The Tokyo air raid is the first in a series of firebombings on sixty-four Japanese cities.

Hundreds of thousands of U.S. troops battle Japanese forces on Okinawa. The island is a potential staging ground for air bases deemed vital for Allied wartime efforts in the Pacific. The battle is even bloodier than Iwo Jima, with more than fourteen thousand U.S. troops killed and seventy thousand Japanese soldiers killed. Up to 150,000 civilians, one-third of Okinawa’s population, die in the cross fire. The U.S. “island hopping” campaigns, ahead of a projected invasion of Japan, prove exceedingly costly and help influence U.S. President Harry S. Truman’s decision to use atomic weapons.

Nazi General Alfred Jodl signs the complete and unconditional surrender of all German armed forces at Allied headquarters in Reims, France, ending the war in the European theater. May 8 is declared Victory-in-Europe (V-E) Day. After the defeat of Nazi Germany, Allies’ battle focus turns to the Pacific theater.

The Interim Committee, a secret high-level group tasked with advising President Truman on nuclear issues, recommends using the atomic bomb against Japanese military targets as soon as possible and without prior warning because the potential loss of U.S. life in an invasion of Japan would be unacceptably high. President Roosevelt had launched the Manhattan Project in 1942 with the aim of developing an atomic bomb. As research advances, Truman’s advisors debate plans to invade Japan and to use an atomic bomb.

The U.S. Army completes the world’s first atomic weapons test at the Los Alamos research site in New Mexico as part of the Manhattan Project. On July 24 at the Potsdam Conference in Germany, Truman informs Stalin of U.S. plans to use an atomic weapon on Japan. The following day, Acting Chief of Staff Thomas T. Handy sends a directive to General Carl Spaatz authorizing the use of the bomb on preselected Japanese cities any time after August 3, once weather permits.

Leaders of the “Big Three”—the United States, Soviet Union, and Great Britain—gather in Potsdam, Germany, to negotiate the terms to end World War II in Europe. Separately, Churchill, Truman, and Republic of China President Chiang Kai-shek issue the Potsdam Declaration outlining the terms of Japan’s surrender, including the unconditional surrender of armed forces, disarmament, and occupation of Japanese territory by Allied forces. Japanese leaders reject the declaration on July 28.

The United States drops the world’s first atomic bomb on the Japanese city of Hiroshima. Between sixty thousand and eighty thousand people die instantly, with thousands others injured and thousands more dying from burns and exposure to radiation. The city suffers extensive destruction, with nearly 67 percent of structures obliterated. In a speech announcing the bombing, Truman threatens Japan’s complete destruction: “If they do not now accept our terms they may expect a rain of ruin from the air, the like of which has never been seen on this earth.”

Foreign minister Vyacheslav Molotov announces the formal Soviet declaration of war against Japan. Soviet troops begin their march on Manchuria, Chinese territory invaded by Japanese forces in 1931. At the end of World War II, millions of Japanese nationals are repatriated from China. In the Soviet Union, thousands of Japanese soldiers are forced into hard labor [PDF] as prisoners of war. Most are repatriated in the first four years after the war, but the last major group of Japanese prisoners is sent back in 1956.

The Bockscar, a U.S. B-29 bomber, drops a second atomic bomb over the industrial valley of Nagasaki. An estimated forty thousand people are killed in the explosion; thousands of others later die from burns or radiation exposure. The yield of the explosion over Nagasaki is later estimated at around 21 kilotons, 40 percent greater than the Hiroshima atomic bomb.

In a radio address to the Japanese public, Emperor Hirohito announces Japan’s acceptance of the terms outlined in the Potsdam Conference for its unconditional surrender. Allied powers celebrate the day as Victory Over Japan (V-J) Day, which effectively marks the end of World War II.

General Douglas MacArthur, Supreme Commander of the Allied Powers (SCAP), arrives at Atsugi Air Base to begin the Allied powers’ occupation of Japan. Unlike occupation in Germany, the SCAP is granted direct control over Japan’s main and immediate surrounding islands, while outlying territory is divided among Allied powers. Tasked by President Truman to oversee the occupation, MacArthur seeks to democratize Japan’s political system and liberalize its economy, emulating a U.S. model.

Foreign Minister Mamoru Shigemitsu signs the Instrument of Surrender on behalf of Emperor Hirohito on the USS Missouri in Tokyo Bay, thereby ending all hostilities and agreeing to all provisions of the Potsdam agreement for Japan’s complete and unconditional surrender. Shortly after, a convoy of more than forty U.S. ships enters the bay with thirteen thousand troops ahead of Japan’s official occupation. During the occupation, the Allied powers establish tribunals to address war crimes and oversee Japan’s political transition.

Emperor Hirohito calls on General MacArthur at the U.S. embassy in Tokyo, marking the first time that an emperor of Japan travels in person to see another leader. This ten-minute exchange is the first meeting between the two, and Hirohito reportedly expresses responsibility for Japan’s wartime actions. Though effectively stripped of real power, Hirohito remains an important symbolic figure. Historians say the Truman administration and MacArthur believed that maintaining Hirohito as head of state provided a stable political climate to enact reforms in Japan.

The Allied powers begin deliberations on Japanese war crimes before the International Military Tribunal for the Far East, a body patterned after Germany’s Nuremberg Trials. The tribunal, which ends in November 1948, presides over the prosecution [PDF] of twenty-eight government officials and military officers facing charges of crimes against peace, conventional war crimes, and crimes against humanity. Emperor Hirohito is not tried. Supporting tribunals are held to prosecute other classes of war crimes across Asia.