atomic bombing of Hiroshima and Nagasaki

Date: 1945

From: Disasters, Accidents, and Crises in American History.

Place: Hiroshima and Nagasaki, Japan
Date: August 6 and August 9, 1945
Type: Use of atomic weapons
Description: The United States dropped two atomic bombs on Japan.
Cause: The proximate cause was the hope of avoiding a projected U.S. land invasion of the Japanese mainland during World War II.
Casualties: An estimated 215,000 people killed
Impact: Led to the surrender of Japan and the inauguration of the age of nuclear weapons


On August 6, 1945, an American B-29 Superfortress bomber nicknamed Enola Gay took off from Tinian Island for the six-and-a-half-hour flight to Hiroshima, Japan's eighth largest city. At a little after eight in the morning, a 10,000-pound atomic bomb equivalent to 20,000 tons of TNT detonated 2,000 feet above the city. The explosion sent a mushroom-shaped cloud 40,000 feet into the atmosphere and destroyed virtually everything within a mile and a half of ground zero. The initial blast killed 80,000 people; as many perished later from wounds and radiation. Hearing nothing from the enemy, the United States launched a second nuclear attack on August 9 against the city of Nagasaki that killed at least 55,000. With Japan in a hopeless position, Emperor Hirohito intervened and instructed his government to accept surrender. On August 15, he broadcast the decision to his subjects, most of whom had never before heard his voice. The detonation of the most powerful weapon the world had ever seen had its intended effect. Japan formally surrendered on September 2, 1945, ending World War II. Ironically but perhaps not surprisingly in view of the enormity of the event, the decision to drop the atomic bombs remains controversial.


The atomic bomb emerged from a herculean effort code-name the Manhattan Project. Its origins traced to a committee of scientists, mainly European refugees including Albert Einstein, who had persuaded President Franklin D. Roosevelt in October 1939 to investigate the possibility of turning a nuclear chain reaction into a superweapon. The project advanced further when the Office of Scientific Research and Development, assigned to study the feasibility of atomic weaponry, recommended the development of a bomb. In January 1942, a month after the Japanese attack on Pearl Harbor plunged the United States into World War II against Japan and Germany, Roosevelt agreed, placing the project under control of the War Department. At a cost of more than $2 billion, the Manhattan Project put 150,000 employees to work at facilities in Hanson, Washington, and Oak Ridge, Tennessee, making fissionable materials, and at Los Alamos, New Mexico, where the bomb was designed.


President Roosevelt died on April 12, 1945, elevating Harry Truman to the presidency. Despite 10 years in the Senate and three months as vice president, Truman knew nothing about the top-secret Manhattan Project. As scientists neared completion of the atomic bomb, Germany surrendered in May 1945, but the war with Japan continued. Two months later, at the Potsdam Conference in Germany, Truman tried to persuade Soviet premier Joseph Stalin to enter the war against Japan. While at the conference, Truman received a telegram indicating that the first test of the atomic bomb in Alamogordo, New Mexico, had proceeded successfully. Emboldened by the news, he warned Japan on July 26 that it must surrender immediately or face "prompt and utter destruction." Japan refused. By early August 1945, the United States had built two more bombs.


Truman did not hesitate in approving the use of the superbomb. "There was never any doubt that the bomb would be used," he later recorded in his Memoirs. "When you deal with a beast you have to treat him as a beast." The president's decision resulted in part from his deference to his military advisers on tactics. Despite reluctance to attack civilian populations, most military leaders favored the deployment of the bomb. Their primary concern was ending the war as quickly as possible and sparing the lives of U.S. servicemen. American forces had suffered a 35 percent casualty rate in subduing the Japanese on Okinawa between April and June 1945. Military planners anticipated that fighting on the mainland would be every bit as bloody, perhaps costing a half-million lives. This prediction was based in part on the belief that the Japanese would fight fervently to the death.


The United States's demand of unconditional surrender made Japanese leaders even more intransigent, as they feared that American terms meant the removal of the emperor. Ethical questions were pushed to the background, if entertained at all. The memory of Pearl Harbor and the cruelty of the Japanese toward American prisoners, especially in the Philippines, weighed on their minds as well. As one air force planner put these sentiments, the United States was at war "with a fanatic enemy whose record of brutality was notorious." Three-quarters of the American public approved of the decision to use the bomb. Memory of Japan's "sneak" attack on Pearl Harbor remained passionate in the United States.


Over the decades since August 1945, scholars and citizens have debated Truman's decision, one of the most momentous and fateful actions any president has ever made. Some have argued that the use of nuclear weapons against Japan constituted a war crime. Others have argued that the use of the atomic bombs was justified because it saved far more lives than it took. Any assessment of Truman's approval of the nuclear attack should balance its moral implications with the historical context in which the decision was made. World War II had turned the world into a vast killing field. An estimated 50 million people died prematurely during the conflict, over half of them noncombatants. Allied planes subjected civilians in German cities to saturation bombing. The U.S. Air Force firebombed virtually every major Japanese city prior to August 6, 1945, with women representing 60 percent of the casualties. The Holocaust perpetrated by the Nazis killed 6 million Jews, and German soldiers murdered millions of Slavs, gypsies, communists, and anti-German partisans. Poland lost one-fifth of its population. Truman reached his decision in a society that had become dulled to the statistics of mass slaughter, yet retained hatred for a purportedly cruel enemy. Right or wrong, the United States fatefully had entered the atomic age.


Campbell, Ballard C. "atomic bombing of Hiroshima and Nagasaki." In Campell, Ballard C., Ph.D., gen. ed. Disasters, Accidents, and Crises in American History. New York: Facts On File, Inc., 2008. American History Online. Facts On File, Inc.
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