Document – Henry Stimson, “The Decision to Use the Atomic Bomb,” Harper’s Magazine, February 1947

Abstract and Keywords

In July, 1945, President Harry Truman, acting on the advice of Secretary of War Henry Stimson and other political and military advisors, ordered the use of atomic weapons against Japan at the earliest possible moment. The bombing of Hiroshima and Nagasaki along with a declaration of war by the Soviet Union, persuaded Emperor Hirohito to accept the United Nations’ demand for unconditional surrender. The initial response in the United States and the world was gratitude and thanksgiving. Soon, however, some observers at home and abroad began to question the necessity and morality of using atomic weapons. In response to this criticism, Henry Stimson (1867–1950) wrote an article for Harper’s Magazine explaining Truman’s decision and his role in it.

Source: Harper’s Magazine, February 1947, 102–107.


In recent months there has been much comment about the decision to use atomic bombs in attacks on the Japanese cities of Hiroshima and Nagasaki. This decision was one of the gravest made by our government in recent years, and it is entirely proper that it should be widely discussed. I have therefore decided to record for all who may be interested my understanding of the events which led up to the attack on Hiroshima on August 6, 1945, on Nagasaki on August 9, and the Japanese decision to surrender, on August 10. No single individual can hope to know exactly what took place in the minds of all of those who had a share in these events, but what follows is an exact description of our thoughts and actions as I find them in the records and in my clear recollection.

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 consisting of Vice President Wallace, General Marshall, Dr. Vannevar Bush, Dr. James B. Conant, and myself. The function of this committee was to advise the President on questions of policy relating to the study of nuclear fission which was then proceeding both in this country and in Great Britain. For nearly four years thereafter I was directly connected with all major decisions of policy on the development and use of atomic energy, and from May 1, 1943, until my resignation as Secretary of War on September 21, 1945, I was directly responsible to the President for the administration of the entire undertaking; my chief advisers in this period were General Marshall, Dr. Bush, Dr. Conant, and Major General Leslie R. Groves, the officer in charge of the project. At the same time I was the President’s senior adviser on the military employment of atomic energy.

The policy adopted and steadily pursued by President Roosevelt and his advisers was a simple one. It was to spare no effort in securing the earliest possible successful development of an atomic weapon. The reasons for this policy were equally simple. The original experimental achievement of atomic fission had occurred in Germany in 1938, and it was known that the Germans had continued their experiments. In 1941 and 1942 they were believed to be ahead of us, and it was vital that they should not be the first to bring atomic weapons into the field of battle. Furthermore, if we should be the first to develop the weapon, we should have a great new instrument for shortening the war and minimizing destruction. At no time, from 1941 to 1945, did I ever hear it suggested by [President Roosevelt], or by any other responsible member of the government, that atomic energy should not be used in the war. All of us of course understood the terrible responsibility involved in our attempt to unlock the doors to such a devastating weapon; President Roosevelt particularly 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. I therefore emphasize that it was our common objective, throughout the war, to be the first to produce an atomic weapon and use it. The possible atomic weapon was considered to be a new and tremendously powerful explosive, as legitimate as any other of the deadly explosive weapons of modern war. The entire purpose was the production of a military weapon; on no other ground could the wartime expenditure of so much time and money have been justified. The exact circumstances in which that weapon might be used were unknown to any of us until the middle of 1945, and when that time came, as we shall presently see, the military use of atomic energy was connected with larger questions of national policy.…

ON JUNE 1 [1945], after its discussions with the Scientific Panel, the Interim Committee unanimously adopted the following recommendations:

  1. (1) The bomb should be used against Japan as soon as possible.

  2. (2) It should be used on a dual target—that is, a military installation or war plant surrounded by or adjacent to houses and other buildings most susceptible to damage, and

  3. (3) It should be used without prior warning [of the nature of the weapon]. One member of the committee, Mr. Bard, later changed his view and dissented from recommendation.

In reaching these conclusions the Interim Committee carefully considered such alternatives as a detailed advance warning or a demonstration in some uninhabited area. Both of these suggestions were discarded as impractical. They were not regarded as likely to be effective in compelling a surrender of Japan, and both of them involved serious risks. Even the New Mexico test would not give final proof that any given bomb was certain to explode when dropped from an airplane. Quite apart from the generally unfamiliar nature of atomic explosives, there was the whole problem of exploding a bomb at a predetermined height in the air by a complicated mechanism which could not be tested in the static test of New Mexico. Nothing would have been more damaging to our effort to obtain surrender than a warning or a demonstration followed by a dud—and this was a real possibility. Furthermore, we had no bombs to waste. It was vital that a sufficient effect be quickly obtained with the few we had.…

The principal political, social, and military objective of the United States in the summer of 1945 was the prompt and complete surrender of Japan. Only the complete destruction of her military power could open the way to lasting peace.

Japan, in July 1945, had been seriously weakened by our increasingly violent attacks. It was known to us that she had gone so far as to make tentative proposals to the Soviet government, hoping to use the Russians as mediators in a negotiated peace. These vague proposals contemplated the retention by Japan of important conquered areas and were therefore not considered seriously. There was as yet no indication of any weakening in the Japanese determination to fight rather than accept unconditional surrender. If she should persist in her fight to the end, she had still a great military force.…

THE adoption of the policy [to use atomic weapons against Japan] was a decision of high politics; once it was accepted by the President, the position of the atomic bomb in our planning became quite clear. I find that I stated in my diary, as early as June 19, that “the last chance warning…must be given before an actual landing of the ground forces in Japan, and fortunately the plans provide for enough time to bring in the sanctions to our warning in the shape of heavy ordinary bombing attack and an attack of S-1.” S-1 was a code name for the atomic bomb.

There was much discussion in Washington about the timing of the warning to Japan. The controlling factor in the end was the date already set for the Potsdam meeting of the Big Three. It was President Truman’s decision that such a warning should be solemnly issued by the U.S. and the U.K. from this meeting, with the concurrence of the head of the Chinese government, so that it would be plain that all of Japan’s principal enemies were in entire unity. This was done, in the Potsdam ultimatum of July 26, which very closely followed the above memorandum of July 2, with the exception that it made no mention of the Japanese Emperor.

On July 28 the Premier of Japan, Suzuki, rejected the Potsdam ultimatum by announcing that it was “unworthy of public notice.” In the face of this rejection we could only proceed to demonstrate that the ultimatum had meant exactly what it said when it stated that if the Japanese continued the war, “the full application of our military power, backed by our resolve, will mean the inevitable and complete destruction of the Japanese armed forces and just as inevitably the utter devastation of the Japanese homeland.”

For such a purpose the atomic bomb was an eminently suitable weapon. The New Mexico test occurred while we were at Potsdam, on July 16. It was immediately clear that the power of the bomb measured up to our highest estimates. We had developed a weapon of such a revolutionary character that its use against the enemy might well be expected to produce exactly the kind of shock on the Japanese ruling oligarchy which we desired, strengthening the position of those who wished peace, and weakening that of the military party.

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 a target of considerable military importance, it had been the ancient capital of Japan and was a shrine of Japanese art and culture. We determined that it should be spared. I approved four other targets including the cities of Hiroshima and Nagasaki.

Hiroshima was bombed on August 6, and Nagasaki on August 9. These two cities were active working parts of the Japanese war effort. One was an army center; the other was naval and industrial. Hiroshima was the headquarters of the Japanese Army defending southern Japan and was a major military storage and assembly point. Nagasaki was a major seaport and it contained several large industrial plants of great wartime importance. We believed that our attacks had struck cities which must certainly be important to the Japanese military leaders, both Army and Navy, and we waited for a result. We waited one day.

MANY accounts have been written about the Japanese surrender. 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. It was based on the Potsdam terms, with a reservation concerning the sovereignty of the Emperor. While the Allied reply made no promises other than those already given, it implicitly recognized the Emperor’s position by prescribing that his power must be subject to the orders of the Allied Supreme Commander. These terms were accepted on August 14 by the Japanese, and the instrument of surrender was formally signed on September 2, in Tokyo Bay. Our great objective was thus achieved, and all the evidence I have seen indicates that the controlling factor in the final Japanese decision to accept our terms of surrender was the atomic bomb.

The two atomic bombs which we had dropped were the only ones we had ready, and our rate of production at the time was very small. Had the war continued until the projected invasion on November 1, additional fire raids of B-29’s would have been more destructive of life and property than the very limited number of atomic raids which we could have executed in the same period. But the atomic bomb was more than a weapon of terrible destruction; it was a psychological weapon. In March 1945 our Air Force had launched its first great incendiary raid on the Tokyo area. In this raid more damage was done and more casualties were inflicted than was the case at Hiroshima. Hundreds of bombers took part and hundreds of tons of incendiaries were dropped. Similar successive raids burned out a great part of the urban area of Japan, but the Japanese fought on. On August 6 one B-29 dropped a single atomic bomb on Hiroshima. Three days later a second bomb was dropped on Nagasaki and the war was over. So far as the Japanese could know, our ability to execute atomic attacks, if necessary by many planes at a time, was unlimited. As Dr. Karl Compton has said, “it was not one atomic bomb, or two, which brought surrender; it was the experience of what an atomic bomb will actually do to a community, plus the dread of many more, that was effective.”

The bomb thus served exactly the purpose we intended. The peace party was able to take the path of surrender, and the whole weight of the Emperor’s prestige was exerted in favor of peace. When the Emperor ordered surrender, and the small but dangerous group of fanatics who opposed him were brought under control, the Japanese became so subdued that the great undertaking of occupation and disarmament was completed with unprecedented ease.

A Personal Summary

In the foregoing pages I have tried to give an accurate account of my own personal observations of the circumstances which led up to the use of the atomic bomb and the reasons which underlay our use of it. To me they have always seemed compelling and clear, and I cannot see how any person vested with such responsibilities as mine could have taken any other course or given any other advice to his chiefs.

Two great nations were approaching contact in a fight to a finish which would begin on November 1, 1945. Our enemy, Japan, commanded forces of somewhat over 5,000,000 armed men. Men of these armies had already inflicted upon us, in our breakthrough of the outer perimeter of their defenses, over 300,000 battle casualties. Enemy armies still unbeaten had the strength to cost us a million more. As long as the Japanese government refused to surrender, we should be forced to take and hold the ground, and smash the Japanese ground armies, by close-in fighting of the same desperate and costly kind that we had faced in the Pacific islands for nearly four years.

In the light of the formidable problem which thus confronted us, I felt that every possible step should be taken to compel a surrender of the homelands, and a withdrawal of all Japanese troops from the Asiatic mainland and from other positions, before we had commenced an invasion. We held two cards to assist us in such an effort. One was the traditional veneration in which the Japanese Emperor was held by his subjects and the power which was thus vested in him over his loyal troops. It was for this reason that I suggested in my memorandum of July 2 that his dynasty should be continued. The second card was the use of the atomic bomb in the manner best calculated to persuade that Emperor and the counselors about him to submit to our demand for what was essentially unconditional surrender, placing his immense power over his people and his troops subject to our orders.

In order to end the war in the shortest possible time and to avoid the enormous losses of human life which otherwise confronted us, I felt that we must use the Emperor as our instrument to command and compel his people to cease fighting and subject themselves to our authority through him, and that to accomplish this we must give him and his controlling advisers a compelling reason to accede to our demands. This reason furthermore must be of such a nature that his people could understand his decision. The bomb seemed to me to furnish a unique instrument for that purpose.

My chief purpose was to end the war in victory with the least possible cost in the lives of the men in the armies which I had helped to raise. In the light of the alternatives which, on a fair estimate, were open to us I believe that no man, in our position and subject to our responsibilities, holding in his hands a weapon of such possibilities for accomplishing this purpose and saving those lives, could have failed to use it and afterwards looked his countrymen in the face.

AS I READ over what I have written, I am aware that much of it, in this year of peace, may have a harsh and unfeeling sound. It would perhaps be possible to say the same things and say them more gently. But I do not think it would be wise. 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.


  1. 1) According to Stimson, why did President Truman decide to use atomic weapons against Japan? How does Stimson justify the decision?

  2. 2) What were the alternatives to surprise military use of the bomb? Why were these alternatives dismissed?

  3. 3) Are Stimson’s arguments convincing? Who is he trying to persuade?

Back to top