The Atomic Bomb and the End of World War II

Hiroshima and Nagasaki and the Invasion of Japan

Aug 22, 2009

The dropping of two atomic bombs on Japan by America in the waning days of World War II was a merciful act that saved millions of Japanese and American lives.

Operation Downfall was the code name for the planned American invasion of mainland Japan. The operation called for the landing of hundreds of thousands of American troops on the Japanese home islands and the assembly of the largest armada in naval history. To defend the sacred soil of their homeland, the Japanese had prepared the whole of the population for a cataclysmic last stand in which millions were expected to perish. Estimates of American casualties far exceeded the total number sustained by the United States in the entire war up to that point. However, less than three months before the planned initial landings, World War II ended with the stroke of a pen in Tokyo Bay.

This peace had been purchased at a cost of over 200,000 Japanese dead. The vast majority of these casualties were civilians who had been incinerated in an instant when the Americans unleashed two of the most powerful weapons in military history on Hiroshima and Nagasaki.

Operations Olympic and Coronet

The first phase of the American invasion was codenamed Operation Olympic and its objective was the capture of the southern third of Kyushu, the southernmost of the Japanese home islands. It involved the capture of a number of smaller surrounding islands and an invasion force of 14 divisions. The accompanying naval armada was to consist of more than 500 ships, including more than 40 aircraft carriers. Olympic was to commence on November 1, 1945. The territory captured during Olympic was to be used as a staging point for the invasion of HonshuIsland and the capture of the Japanese capital.

Operation Coronet would have dwarfed every amphibious operation before or since. The D-Day landings, comparatively, would have seemed like a sideshow. While the forces necessary for Olympic could have drawn together from forces already in the Pacific, Coronet would have required the redeployment of hundreds of thousands of men stationed in Europe and the transfer of millions of tons of war material. Its objective was the landing of 25 divisions on the Honshu plain south of Tokyo and the eventual capture of the capital.

Casualty Estimates of Invading Japan

Predictions of the number of dead and wounded on both sides varied widely. The U.S. Joint Chiefs of Staff estimated more than 1.5 million total American casualties for both operations. A study done for the office of the Secretary of War estimated up to 4 million American and 10 million Japanese casualties. Predictions made by American commanders Nimitz and Macarthur were considerably lower. For comparison, the total number of American battle fatalities in all theatres of World War II was less than 400,000. In anticipation of the massive casualties, the War Department commissioned the manufacture of nearly 500,000 Purple Heart medals.

One of the factors that led to the disparate casualty estimates was the uncertainty surrounding the participation of Japanese civilians in the defense of the home islands. After the fanatical defense of Okinawa, American military leaders became increasingly concerned about the zealotry displayed by the Japanese as the American island hopping strategy inched closer to the home islands. The Japanese had assembled 10,000 aircraft on the home islands to be used in Kamikaze attacks and millions of civilians had been armed by the Japanese government.

The decision by U.S. President Harry Truman to use the atomic bomb on Japan has been widely criticized in both Japan and America. Hundreds of thousands of innocent civilians were vaporized in an instant and two bustling cities were charred beyond recognition. However horrible the aftermath, and it was horrible, it forced the Japanese to see their situation for what it was: Hopeless. To continue fighting would have meant the decimation of the Japanese homeland and untold suffering for its people. It made them do something that was abhorrent to the Japanese character: Sue for peace.

World War II ended on September 2, 1945 with the signing of the act of unconditional surrender by Japan, the United States, and its allies. That surrender, less than two months before the scheduled commencement of Operation Olympic, saved millions of lives and the Japanese nation. That surrender was only made possible by atomic weaponry and those who criticize its use might consider that in war the manner of one's murder, be it by bullet, knife, or nuclear fireball, matters little to the deceased.

The military option that allows the greatest number of men to return home to their families is invariably the best choice. The atomic bombs killed 200,000 people, but millions of men, women, and children were alive at the end of World War II that would have been killed had it not been for their use. With this in mind, it is difficult to fault Truman's decision, since more than 60 years after the Japanese surrender, after Korea, Vietnam, Iraq and a hundred other conflicts, the 500,000 Purple Heart medals commissioned in advance of the invasion of Japan are still being awarded to American servicemen today.

Downfall: The End of the Imperial Japanese Empire by Richard B. Frank. Random House: 1999.

Code-Name Downfall by Thomas Allen and Norman Polmar by John Skates. Simon and Schuster: 1995.

The Invasion of Japan: Alternative to the Bomb by John Ray Skates. University of South Carolina Press: 1994.

The copyright of the article The Atomic Bomb and the End of World War II in WW II History is owned by Matthew Miller. Permission to republish The Atomic Bomb and the End of World War II in print or online must be granted by the author in writing.