Editor’s Note: President Harry S. Truman responded to this article in the weeks after it was published.

About a week after V-J Day, I was one of a small group of scientists and engineers interrogating an intelligent, well-informed Japanese Army officer in Yokohama. We asked him what, in his opinion, would have been the next major move if the war had continued. He replied: "You would probably have tried to invade our homeland with a landing operation on Kyushu about November 1. I think the attack would have been made on such and such beaches."



"Could you have repelled this landing?" we asked, and he answered: "It would have been a very desperate fight, but I do not think we could have stopped you."



"What would have happened then?" we asked.



He replied: "We would have kept on fighting until all Japanese were killed, but we would not have been defeated," by which he meant that they would not have been disgraced by surrender.



It is easy now, after the event, to look back and say that Japan was already a beaten nation, and to ask what therefore was the justification for the use of the atomic bomb to kill so many thousands of helpless Japanese in this inhuman way; furthermore, should we not better have kept it to ourselves as a secret weapon for future use, if necessary? This argument has been advanced often, but it seems to me utterly fallacious.



I had, perhaps, an unusual opportunity to know the pertinent facts from several angles, yet I was without responsibility for any of the decisions. I can therefore speak without doing so defensively. While my role in the atomic bomb development was a very minor one, I was a member of the group called together by Secretary of War Stimson to assist him in plans for its test, use, and subsequent handling. Then, shortly before Hiroshima, I became attached to General MacArthur in Manila, and lived for two months with his staff. In this way I learned something of the invasion plans and of the sincere conviction of these best-informed officers that a desperate and costly struggle was still ahead. Finally, I spent the first month after V-J Day in Japan, where I could ascertain at first hand both the physical and the psychological state of that country. Some of the Japanese whom I consulted were my scientific and personal friends of long standing.



From this background I believe, with complete conviction, that the use of the atomic bomb saved hundreds of thousands—perhaps several millions—of lives, both American and Japanese; that without its use the war would have continued for many months; that no one of good conscience knowing, as Secretary Stimson and the Chiefs of Staff did, what was probably ahead and what the atomic bomb might accomplish could have made any different decision. Let some of the facts speak for themselves.



Was the use of the atomic bomb inhuman? All war is inhuman. Here are some comparisons of the atomic bombing with conventional bombing. At Hiroshima the atomic bomb killed about 80,000 people, pulverized about five square miles, and wrecked an additional ten square miles of the city, with decreasing damage out to seven or eight miles from the center. At Nagasaki the fatal casualties were 45,000 and the area wrecked was considerably smaller than at Hiroshima because of the configuration of the city.



Compare this with the results of two B-29 incendiary raids over Tokyo. One of these raids killed about 125,000 people, the other nearly 100,000.



Of the 210 square miles of greater Tokyo, 85 square miles of the densest part was destroyed as completely, for all practical purposes, as were the centers of Hiroshima and Nagasaki; about half the buildings were destroyed in the remaining 125 square miles; the number of people driven homeless out of Tokyo was considerably larger than the population of greater Chicago. These figures are based on information given us in Tokyo and on a detailed study of the air reconnaissance maps. They may be somewhat in error but are certainly of the right order of magnitude.



Was Japan already beaten before the atomic bomb? The answer is certainly "yes" in the sense that the fortunes of war had turned against her. The answer is "no" in the sense that she was still fighting desperately and there was every reason to believe that she would continue to do so; and this is the only answer that has any practical significance.



General MacArthur's staff anticipated about 50,000 American casualties and several times that number of Japanese casualties in the November 1 operation to establish the initial beachheads on Kyushu. After that they expected a far more costly struggle before the Japanese homeland was subdued. There was every reason to think that the Japanese would defend their homeland with even greater fanaticism than when they fought to the death on Iwo Jima and Okinawa. No American soldier who survived the bloody struggles on these islands has much sympathy with the view that battle with the Japanese was over as soon as it was clear that their ultimate situation was hopeless. No, there was every reason to expect a terrible struggle long after the point at which some people can now look back and say, "Japan was already beaten."



A month after our occupation I heard General MacArthur say that even then, if the Japanese government lost control over its people and the millions of former Japanese soldiers took to guerrilla warfare in the mountains, it could take a million American troops ten years to master the situation.



That this was not an impossibility is shown by the following fact, which I have not seen reported. We recall the long period of nearly three weeks between the Japanese offer to surrender and the actual surrender on September 2. This was needed in order to arrange details: of the surrender and occupation and to permit the Japanese government to prepare its people to accept the capitulation. It is not generally realized that there was threat of a revolt against the government, led by an Army group supported by the peasants, to seize control and continue the war. For several days it was touch and go as to whether the people would follow their government in surrender.



The bulk of the Japanese people did not consider themselves beaten; in fact they believed they were winning in spite of the terrible punishment they had taken. They watched the paper balloons take off and float eastward in the wind, confident that these were carrying a terrible retribution to the United States in revenge for our air raids.



We gained a vivid insight into the state of knowledge and morale of the ordinary Japanese soldier from a young private who had served through the war in the Japanese Army. He had lived since babyhood in America, and had graduated in 1940 from Massachusetts Institute of Technology. This lad, thoroughly American in outlook, had gone with his family to visit relatives shortly after his graduation. They were caught in the mobilization and he was drafted into the Army.



This young Japanese told us that all his fellow soldiers believed that Japan was winning the war. To them the losses of Iwo Jima and Okinawa were parts of a grand strategy to lure the American forces closer and closer to the homeland, until they could be pounced upon and utterly annihilated. He himself had come to have some doubts as a result of various inconsistencies in official reports. Also he had seen the Ford assembly line in operation and knew that Japan could not match America in war production. But none of the soldiers had any inkling of the true situation until one night, at ten-thirty, his regiment was called to hear the reading of the surrender proclamation.



Did the atomic bomb bring about the end of the war? That it would do so was the calculated gamble and hope of Mr. Stimson, General Marshall, and their associates. The facts are these. On July 26, 1945, the Potsdam Ultimatum called on Japan to surrender unconditionally. On July 29 Premier Suzuki issued a statement, purportedly at a cabinet press conference, scorning as unworthy of official notice the surrender ultimatum, and emphasizing the increasing rate of Japanese aircraft production. Eight days later, on August 6, the first atomic bomb was dropped on Hiroshima; the second was dropped on August 9 on Nagasaki; on the following day, August 10, Japan declared its intention to surrender, and on August 14 accepted the Potsdam terms.



On the basis of these facts, I cannot believe that, without the atomic bomb, the surrender would have come without a great deal more of costly struggle and bloodshed.



Exactly what role the atomic bomb played will always allow some scope for conjecture. A survey has shown that it did not have much immediate effect on the common people far from the two bombed cities; they knew little or nothing of it. The even more disastrous conventional bombing of Tokyo and other cities had not brought the people into the mood to surrender.



The evidence points to a combination of factors. (1) Some of the more informed and intelligent elements in Japanese official circles realized that they were fighting a losing battle and that complete destruction lay ahead if the war continued. These elements, however, were not powerful enough to sway the situation against the dominating Army organization, backed by the profiteering industrialists, the peasants, and the ignorant masses. (2) The atomic bomb introduced a dramatic new element into the situation, which strengthened the hands of those who sought peace and provided a face-saving argument for those who had hitherto advocated continued war. (3) When the second atomic bomb was dropped, it became clear that this was not an isolated weapon, but that there were others to follow. With dread prospect of a deluge of these terrible bombs and no possibility of preventing them, the argument for surrender was made convincing. This I believe to be the true picture of the effect of the atomic bomb in bringing the war to a sudden end, with Japan's unconditional surrender.



If the atomic bomb had not been used, evidence like that I have cited points to the practical certainty that there would have been many more months of death and destruction on an enormous scale. Also the early timing of its use was fortunate for a reason which could not have been anticipated. If the invasion plans had proceeded as scheduled, October, 1945, would have seen Okinawa covered with airplanes and its harbors crowded with landing craft poised for the attack. The typhoon which struck Okinawa in that month would have wrecked the invasion plans with a military disaster comparable to Pearl Harbor.



These are some of the facts which lead those who know them, and especially those who had to base decisions on them, to feel that there is much delusion and wishful thinking among those after-the-event strategists who now deplore the use of the atomic bomb on the ground that its use was inhuman or that it was unnecessary because Japan was already beaten. And 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.



If 500 bombers could wreak such destruction on Tokyo, what will 500 bombers, each carrying an atomic bomb, do to the City of Tomorrow? It is this deadly prospect which now lends such force to the two basic policies of our nation on this subject: (1) We must strive generously and with all our ability to promote the United Nations' effort to assure future peace between nations; but we must not lightly surrender the atomic bomb as a means for our own defense. (2) We should surrender or share it only when there is adopted an international plan to enforce peace in which we can have great confidence.