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World War II (1939–1945)

History SparkNotes

The Fall of Japan

The Fall of Germany

Study Questions & Essay Topics

March 1945 Allies begin mass bombing raids of Tokyo and other cities
July 16 United States successfully tests first atomic bomb
July 26 Potsdam Declaration signed
August 6 United States drops atomic bomb on Hiroshima
August 8 USSR enters war against Japan
August 9 United States drops atomic bomb on Nagasaki USSR invades Manchuria
August 15 Hirohito announces Japan’s surrender
September 2 Japan signs formal surrender
Key People
Harry S Truman -  33rd U.S. president; after death of Roosevelt, made decision to drop atomic bombs on Hiroshima and Nagasaki in August 1945
Curtis LeMay -  U.S. general who orchestrated brutal incendiary bombing campaign against major Japanese cities in March 1945

The Tokyo Air Raids

During the same months that Allied forces in Europe were closing in on Germany, Allied forces in the Pacific were closing in on Japan. In March 1945, the U.S. Air Force began a series of heavy bombing campaigns against major Japanese cities. These attacks were the brainchild of General Curtis LeMay, who headed the 21st Bomber Command. The operations used America’s new strategic bomber, the B-29 , and directly targeted the Japanese civilian population in addition to industrial and military targets. The strategy was simply to destroy the Japanese will to resist.

Many of these raids were conducted on the capital of Tokyo itself, though other cities such as Kobe were also hit. In the spring and summer of 1945, the severity of these air raids grew exponentially, some causing firestorms that produced death tolls in the hundreds of thousands. By late summer, little of Tokyo and the other targeted cities were left standing.

The Potsdam Declaration

Between July 17 and August 2, 1945, Harry S Truman of the United States, Winston Churchill of Britain (and later Clement Atlee, who replaced him as prime minister during the conference), and Joseph Stalin of the USSR met in Potsdam, Germany, with other Allied leaders to discuss the future administration of Germany. On July 26, the three also held a special meeting to settle on the terms of surrender for Japan in order to end the war. The agreement was set forth in a document known as the Potsdam Declaration. In short, it demanded an unconditional surrender that included the complete demilitarization of the country and the replacement of Japan’s current leadership by a “peacefully inclined and responsible government.”

The Manhattan Project

During the summer of 1945, American scientists succeeded in completing a working atomic bomb, which was tested a single time, on July 16, at a remote location in New Mexico. Scientists around the world had theorized about the concept of such a weapon for years, and active research on its development had been taking place not only in the United States but also in Nazi Germany, Japan, and the USSR. The American effort, which was conducted with substantial help from Canada and Britain, was code-named the Manhattan Project. Shortly after the July test, the Truman administration began seriously to consider using the bomb against Japan. Eventually, Truman made the difficult decision to do so, in spite of considerable resistance from U.S. military leaders. Despite the fact that the bomb would kill tens of thousands of innocents, Truman felt that it would ultimately save both U.S. military and Japanese civilian casualties that would inevitably result from a ground invasion of Japan.

Hiroshima and Nagasaki

The first atomic bomb was dropped from a B-29 called the Enola Gay on the morning of August 6, 1945, onto the city of Hiroshima. The blast obliterated most of the central city, killing 80,000 in a single moment. By the end of the year, 60,000 more victims would die from radiation poisoning, and thousands more would die in the years to come, from cancer and other long-term effects of the radiation. It is estimated that the total death toll from Hiroshima was well over 200,000.

The immediate reaction to the bomb in Japan was one of total incomprehension. All communications with Hiroshima were lost, and rumors quickly spread that the city had vanished in some kind of cataclysmic explosion. Yet Japanese military radar had indicated that only a few isolated planes had been in the area. The Japanese would learn the truth sixteen hours following the explosion, when the U.S. government released a public statement explaining what had taken place. Three days later, on August 9, a second atomic bomb was dropped on the port city of Nagasaki with similarly devastating results.

Japan Surrenders

The day before the Nagasaki bombing, the Soviet Union entered the war against Japan and commenced an attack on the Chinese province of Manchuria, which was still held by the Japanese. The combination of the atomic bombings with the potential threat of a full-scale invasion of Japan by the USSR was enough to remove any hope that Japan may have held for continuing the war. On August 15, 1945, Emperor Hirohito announced Japan’s capitulation in accordance with the Potsdam Declaration. A formal surrender was signed on September 2 aboard the battleship USS Missouri.

Truman’s Decision

The campaign against Japan at the end of the war and the use of the atomic bomb have long been the subject of debate and controversy around the world, especially outside the United States. Critics contend that Japan was already on the verge of surrender by late summer 1945 and that the atomic bombings were superfluous, needlessly killing hundreds of thousands of people. The same was said about the mass incendiary bombing attacks on Tokyo and other cities, which killed even more people than did the atomic bombs, although without as many long-term effects.

On the other hand, proponents of the bombings say that battles such as Iwo Jima and Okinawa demonstrated that the Japanese population was prepared to fight to the last man and that only a weapon as overpowering as the atomic bomb could have ended the war without unfathomable casualties. Indeed, the only alternative to the bombings would have been a ground invasion using U.S. troops, which would have been extremely costly in both American and Japanese lives. The argument has thus been made that such a ground invasion would have cost far more Japanese lives than the Nagasaki and Hiroshima bombings combined.

Moreover, evidence suggests that external political factors played a significant part in the decision to drop the atomic bombs. The Manhattan Project had been very expensive, and the Truman administration felt pressured to demonstrate that the weapon actually could be used effectively for military purposes. Furthermore, tensions were growing with the Soviet Union over the division of Eastern Europe, and the United States may have wished to demonstrate its newfound power.

Finally, the atomic bomb was a new, untested technology. The worldwide cultural taboo surrounding such weapons did not exist at the time, and in general there was less understanding of the long-term effects of their use—only one atomic bomb had ever been tested successfully. Frighteningly, as powerful as the Hiroshima and Nagasaki bombs were, their destructive power was small in comparison with the nuclear weapons of today.

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