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It was in the fall of 1941 that the question of atomic energy was first brought directly to my attention. At that time President Roosevelt appointed a committee to advise him on nuclear fission. The policy adopted and steadily pursued by the president and his advisers was a simple one: to spare no effort in securing the earliest possible successful development of an atomic weapon. All of us of course understood the terrible responsibility involved in our attempt to unlock the doors to such a devastating weapon; President Roosevelt spoke to me many times of his own awareness of the catastrophic potentialities of our work. But we were at war, and the work must be done.

The exact circumstances in which that weapon might be used were unknown to any of us until the middle of 1945. The principal political, social, and military objective of the United States that summer was the prompt and complete surrender of Japan. Only the complete destruction of her military power could open the way to lasting peace.

Because of the importance of the atomic mission against Japan, the detailed plans were brought to me by the military staff for approval. With President Truman’s warm support I struck off the list of suggested targets the city of Kyoto. Although it was of considerable military importance, it had been the ancient capital of Japan and was a shrine of art and culture. I approved four other targets.

Hiroshima was bombed on August 6, and Nagasaki on August 9. These two cities were active parts of the Japanese war effort. One was an army center; the other was naval and industrial.

After a prolonged Japanese cabinet session in which the deadlock was broken by the emperor himself, the offer to surrender was made on August 10. All the evidence I have seen indicates that the controlling factor in the decision to accept our terms of surrender was the atomic bomb. The atomic bomb was more than a weapon of terrible destruction; it was a psychological weapon.

As I look back over the five years of my service as secretary of war, I see too many stern and heartrending decisions to be willing to pretend that war is anything else than what it is. The face of war is the face of death; death is an inevitable part of every order that a wartime leader gives. The decision to use the atomic bomb was a decision that brought death to over a hundred thousand Japanese. No explanation can change that fact and I do not wish to gloss it over. But this deliberate, premeditated destruction was our least abhorrent choice. The destruction of Hiroshima and Nagasaki put an end to the Japanese war. It stopped the fire raids, and the strangling blockade; it ended the ghastly specter of a clash of great land armies.

In this last great action of the Second World War we were given final proof that war is death. War in the twentieth century has grown steadily more barbarous, more destructive, more debased in all its aspects. Now, with the release of atomic energy, man’s ability to destroy himself is very nearly complete. The bombs dropped on Hiroshima and Nagasaki ended a war. They also made it wholly clear that we must never have another war. This is the lesson men and leaders everywhere must learn, and I believe that when they learn it they will find a way to lasting peace. There is no other choice.

From “The Decision to Use the Atomic Bomb,” which appeared in the February 1947 issue of Harper’s Magazine. The complete essay — along with the magazine’s entire 167-year archive — is available online at

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March 1946

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