The historic message of the first explosion of an atomic bomb was flashed to me in a message from Secretary of War Stimson on the morning of July 16. The most secret and the most daring enterprise of the war had succeeded. We were now in possession of a weapon that would not only revolutionize war, but could alter the course of history and civilization. This news reached me at Potsdam the day after I had arrived for the conference of the Big Three.
Preparations were being rushed for the test atomic explosion at Alamogordo, New Mexico, at the time I had to leave for Europe, and on the voyage over I had been anxiously awaiting word on the results. I had been told of many predictions by the scientists, but no one was certain of the outcome of this full-scale atomic explosion. As I read the message from Stimson, I realized that the test not only met the most optimistic expectation of the scientists, but that the United States had in its possession an explosive force of unparalleled power.
Stimson flew to Potsdam the next day to see me and brought with him the full details of the test. I received him at once and called in Secretary of State Byrnes, Admiral Leahy, General Marshall, General Arnold, and Admiral King to join us at my office at the Little White House. We reviewed our military strategy in the light of this revolutionary development. We were not ready to make use of this weapon against the Japanese, although we did not know as yet what effect the new weapon might have, physically or psychologically, when used against the enemy. For that reason, the military advised that we go ahead with the existing military plans for the invasion of the Japanese home islands.
At Potsdam, as elsewhere, the secret of the atomic bomb was kept closely guarded. We did not extend the very small circle of Americans who knew about it. Churchill naturally knew about the atomic bomb project from its very beginning, because it had involved the pooling of British and American technical skill.
On July 24, I casually mentioned to Stalin that we had a new weapon of unusual destructive force. The Russian Premier showed no special interest. All he said was that he was glad to hear it and hoped we would make “good use of it against the Japanese.”
A month before the test explosion of the atomic bomb, the service Secretaries and the Joint Chiefs of Staff had laid their detailed plans for the defeat of Japan before me for approval. There had apparently been some differences of opinion as to the best route to be followed, but these had evidently been reconciled, for when General Marshall had presented his plan for a two-phase invasion of Japan, Admiral King and General Arnold had supported the proposal heartily.
The Army plan envisaged an amphibious landing in the fall of 1945 on the island of Kyushu, the southernmost of the Japanese home islands. This would be accomplished by our Sixth Army, under the command of General Walter Krueger. The first landing would then be followed approximately four months later by a second great invasion, which would be carried out by our Eighth and Tenth Armies, followed by the First Army transferred from Europe, all of which would go ashore in the Kanto plains area near Tokyo. In all, it had been estimated that it would require until the late fall of 1946 to bring Japan to her knees.
This was a formidable conception, and all of us realized fully that the fighting would be fierce and the losses heavy. But it was hoped that some of Japan’s forces would continue to be preoccupied in China and others would be prevented from reinforcing the home islands if Russia were to enter the war.
There was, of course, always the possibility that the Japanese might choose to surrender sooner. Our air and fleet units had begun to inflict heavy damage on industrial and urban sites in Japan proper. Except in China, the armies of the Mikado had been pushed back everywhere in relentless successions of defeats.
Acting Secretary of State Grew had spoken to me in late May about issuing a proclamation that would urge the Japanese to surrender, but would assure them that we would permit the Emperor to remain as head of the state. Grew backed this with arguments taken from his ten years’ experience as our Ambassador in Japan, and I told him that I had already given thought to this matter myself and that it seemed to me a sound idea. Grew had a draft of a proclamation with him, and I instructed him to send it by the customary channels to the Joint Chiefs and the State-War-Navy Coordinating Committee in order that we might get the opinions of all concerned before I made my decision.
On June 18, Grew reported that the proposal had met with the approval of his Cabinet colleagues and of the Joint Chiefs. The military leaders also discussed the subject with me when they reported the same day. Grew, however, favored issuing the proclamation at once, to coincide with the closing of the campaign on Okinawa, while the service chiefs were of the opinion that we should wait until we were ready to follow a Japanese refusal with the actual assault of our invasion forces.
It was my decision then that the proclamation to Japan should be issued from the forthcoming conference at Potsdam. This, I believed, would clearly demonstrate to Japan and to the world that the Allies were united in their purpose. By that time, also, we might know more about two matters of significance for our future effort: the participation of the Soviet Union and the atomic bomb. We knew that the bomb would receive its first test in mid-July. If the test of the bomb was successful, I wanted to afford Japan a clear chance to end the fighting before we made use of this newly gained power. If the test should fail, then it would be even more important to us to bring about a surrender before we had to make a physical conquest of Japan. General Marshall told me that it might cost half a million American lives to force the enemy’s surrender on his home grounds.
But the test was now successful. The entire development of the atomic bomb had been dictated by military considerations. The idea of the atomic bomb had been suggested to President Roosevelt by the famous and brilliant Dr. Albert Einstein, and its development turned out to be a vast undertaking. It was the achievement of the combined efforts of science, industry, labor, and the military, and it had no parallel in history. The men in charge, and their staffs, worked under extremely high pressure, and the whole enormous task required the services of more than 100,000 men and immense quantities of material. It required over two and a half years and necessitated the expenditure of $2.5 billion.
Only a handful of the thousands of men who worked in these plants knew what they were producing. So strict was the secrecy imposed that even some of the highest-ranking officials in Washington had not the slightest idea of what was going on. I did not. Before 1939, it had been generally agreed among scientists that it was theoretically possible to release energy from the atom. In 1940, we had begun to pool with Great Britain all scientific knowledge useful to war, although Britain was at war at that time and we were not. Following this - in 1942 - we learned that the Germans were at work on a method to harness atomic energy for use as a weapon of war. This, we understood, was to be added to the V-l and V-2 rockets with which they hoped to conquer the world. They failed, of course, and for this we can thank Providence. But now a race was on to make the atomic bomb - a race that became “the battle of the laboratories.”
It was under the general policy of pooling knowledge between our nation and Great Britain that research on the atomic bomb started in such feverish secrecy. American and British scientists joined in the race against the Germans. We in America had available a great number of distinguished scientists in many related fields of knowledge, and we also had another great advantage. We could provide the tremendous industrial and economic resources required for the project - a vastly expensive project - without injury to our war production program. Furthermore, our plants were far removed from the reach of enemy bombing. Britain, whose scientists had initiated the project and were contributing much of the original atomic data, was constantly exposed to enemy bombing and, when she started the atomic research, also faced the possibility of invasion.
For these reasons, Roosevelt and Churchill agreed to pool the research and concentrate all of the work on the development of the project within the United States. Working together with the British, we thus made it possible to achieve a great scientific triumph in the field of atomic energy. Nevertheless, basic and historic as this event was, it had to be considered at the time as relatively incidental to the far-flung war we were fighting in the Pacific at terrible cost in American lives.
We could hope for a miracle, but the daily tragedy of a bitter war crowded in on us. We labored to construct a weapon of such overpowering force that the enemy could be forced to yield swiftly once we could resort to it. This was the primary aim of our secret and vast effort. But we also had to carry out the enormous effort of our basic and traditional military plans.
The task of creating the atomic bomb had been entrusted to a special unit of the Army Corps of Engineers, the so-called Manhattan District, headed by Major General Leslie R. Groves. The primary effort, however, had come from British and American scientists working in laboratories and offices scattered throughout the nation.
Dr. J. Robert Oppenheimer, the distinguished physicist from the University of California, had set up the key establishment in the whole process at Los Alamos, New Mexico. More than any other one man, Oppenheimer is to be credited with the achievement of the completed bomb.
My own knowledge of these developments had come about only after I became President, when Secretary Stimson had given me the full story. He had told me at that time that the project was nearing completion and that a bomb could be expected within another four months. It was at his suggestion, too, that I had then set up a committee of top men and had asked them to study with great care the implications the new weapon might have for us.
Secretary Stimson headed this group as chairman, and the other members were George L. Harrison, president of the New York Life Insurance Company, who was then serving as a special assistant to the Secretary of War; James F. Byrnes, as my personal representative; Ralph A. Bard, Under Secretary of the Navy; Assistant Secretary William L. Clayton for the State Department; and three of our most renowned scientists - Dr. Vannevar Bush, president of the Carnegie Institution of Washington and Director of the Office of Scientific Research and Development; Dr. Karl T. Compton, president of the Massachusetts Institute of Technology and Chief of Field Service in the Office of Scientific Research and Development; and Dr. James B. Conant, president of Harvard University and chairman of the National Defense Research Committee.
This committee was assisted by a group of scientists, of whom those most prominently connected with the development of the atomic bomb were Dr. Oppenheimer, Dr. Arthur H. Compton, Dr. E. O. Lawrence, and the Italian-born Dr. Enrico Fermi. The conclusions reached by these men, both in the advisory committee of scientists and in the larger committee, were brought to me by Secretary Stimson on June 1.
It was their recommendation that the bomb be used against the enemy as soon as it could be done. They recommended further that it should be used without specific warning and against a target that would clearly show its devastating strength. I had realized, of course, that an atomic bomb explosion would inflict damage and casualties beyond imagination. On the Other hand, the scientific advisers of the committee reported, “We can propose no technical demonstration likely to bring an end to the war; we see no acceptable alternative to direct military use.” It was their conclusion that no technical demonstration they might propose, such as over a deserted island, would be likely to bring the war to an end. It had to be used against an enemy target.
The final decision of where and when to use the atomic bomb was up to me. Let there be no mistake about it, I regarded the bomb as a military weapon and never had any doubt that it should be used. The top military advisers to the President recommended its use, and when I talked to Churchill, he unhesitatingly told me that he favored the use of the atomic bomb if it might aid to end the war.
In deciding to use this bomb, I wanted to make sure that it would be used as a weapon of war in the manner prescribed by the laws of war. That meant that I wanted it dropped on a military target. I had told Stimson that the bomb should be dropped as nearly as possibly upon a war production center of prime military importance.
Stimson’s staff had prepared a list of cities in Japan that might serve as targets. Kyoto, though favored by General Arnold as a center of military activity, was eliminated when Secretary Stimson pointed out that it was a cultural and religious shrine of the Japanese.
Four cities were finally recommended as targets: Hiroshima, Kokura, Niigata, and Nagasaki. They were listed in that order as targets for the first attack. The order of selection was in accordance with the military importance of these cities, but allowance would be given for weather conditions at the time of the bombing. Before the selected targets were approved as proper for military purposes, I personally went over them in detail with Stimson, Marshall, and Arnold, and we discussed the matter of timing and the final choice of the first target.
General Spaatz, who commanded the Strategic Air Forces, which would deliver the bomb on the target, was given some latitude as to when and on which of the four targets the bomb would be dropped. That was necessary because of weather and other operational considerations. In order to get preparations under way, the War Department was given orders to instruct General Spaatz that the first bomb would be dropped as soon after August 3 as weather would permit. The order to General Spaatz read as follows:
24 July 1945
TO: General Carl Spaatz
Commanding General
United States Army Strategic Air Forces
1. The 509 Composite Group, 20th Air Force will deliver its first special bomb as soon as weather will permit visual bombing after about 3 August 1945 on one of the targets: Hiroshima, Kokura, Niigata and Nagasaki. To carry military and civilian scientific personnel from the War Department to observe and record the effects of the explosion of the bomb, additional aircraft will accompany the airplane carrying the bomb. The observing planes will stay several miles distant from the point of impact of the bomb.
2. Additional bombs will be delivered on the above targets as soon as made ready by the project staff. Further instructions will be issued concerning targets other than those listed above.
3. Dissemination of any and all information concerning the use of the weapon against Japan is reserved to the Secretary of War and the President of the United States. No communiqué on the subject or release of information will be issued by Commanders in the field without specific prior authority. Any news stories will be sent to the war Department for special clearance.
4. The foregoing directive is issued to you by direction and with the approval of the Secretary of War and the Chief of Staff, U.S.A. It is desired that you personally deliver one copy of this directive to General MacArthur and one copy to Admiral Nimitz for their information.
/s/ Thos. T. Handy
General, GSC
Acting Chief of Staff
With this order the wheels were set in motion for the first use of an atomic weapon against a military target. I had made the decision. I also instructed Stimson that the order would stand unless I notified him that the Japanese reply to our ultimatum was acceptable.
A specialized B-29 unit, known as the 509th Composite Group, had been selected for the task, and seven of the modified B-29’s, with pilots and crews, were ready and waiting for orders. Meanwhile, ships and planes were rushing the materials for the bomb, and specialists to assemble them, to the Pacific island of Tinian in the Marianas.
On July 28, Radio Tokyo announced that the Japanese government would continue to fight. There was no formal reply to the joint ultimatum of the United States, the United Kingdom, and China. There was no alternative now. The bomb was scheduled to be dropped after August 3, unless Japan surrendered before that day.
On August 6, the fourth day of the journey home from Potsdam, came the historic news that shook the world. I was eating lunch with members of the Augusta’s crew when Captain Frank Graham, White House Map Room watch officer, handed me the following message:
TO THE PRESIDENT
FROM THE SECRETARY OF WAR
Big bomb dropped on Hiroshima August 5 at 7:15 p.m. Washington time. First reports indicate complete success which was even more conspicuous than earlier test.
I was greatly moved. I telephoned Byrnes aboard ship to give him the news and then said to the group of sailors around me, “This is the greatest thing in history. It’s time for us to get home.”
A few minutes later, a second message was handed to me. It read as follows:
Following info regarding Manhattan received. “Hiroshima bombed visually with only one tenth cover at 052315A. There was no fighter opposition and no flak. Parsons reports 15 minutes after drop as follows: ‘Results clear cut successful in all respects. Visible effects greater than in any test. Conditions normal in airplane following delivery.’”
When I had read this, I signaled to the crew in the mess hall that I wished to say something. I then told them of the dropping of a powerful new bomb which used an explosive 20,000 times as powerful as a ton of TNT. I went to the wardroom, where I told the officers, who were at lunch, what had happened. I could not keep back my expectation that the Pacific war might now be brought to a speedy end.
A few minutes later, the ship’s radio receivers began to carry news bulletins from Washington about the atomic bomb, as well as a broadcast of the statement I had authorized just before leaving Germany. Shortly afterward, I called a press conference of the correspondents on board and told them something of the long program of research and development that lay behind this successful assault.
My statements on the atomic bomb, which had been released in Washington by Stimson, read in part as follows:
“. . . But the greatest marvel is not the size of the enterprise, its secrecy, nor its cost, but the achievement of scientific brains in putting together infinitely complex pieces of knowledge held by many men in different fields of science into a workable plan. And hardly less marvelous has been the capacity of industry to design, and of labor to operate, the machines and methods to do things never done before, so that the brain child of many minds came forth in physical shape and performed as it was supposed to do. Both science and industry worked under the direction of the United States Army, which achieved a unique success in managing so diverse a problem in the advancement of knowledge in an amazingly short time. It is doubtful if such another combination could be got together in the world. What has been done is the greatest achievement of organized science in history. It was done under high pressure and without failure.
“We are now prepared to obliterate more rapidly and completely every productive enterprise the Japanese have above ground in any city. We shall destroy their docks, their factories, and their communications. Let there be no mistake, we shall completely destroy Japan’s power to make war.
“It was to spare the Japanese people from utter destruction that the ultimatum of July 26 was issued at Potsdam. Their leaders promptly rejected that ultimatum. If they do not now accept our terms, they may expect a rain of ruin from the air, the like of which has never been seen on this earth. Behind this air attack will follow sea and land forces in such numbers and power as they have not yet seen and with the fighting skill of which they are already well aware.
“. . . The fact that we can release atomic energy ushers in a new era in man’s understanding of nature’s forces. Atomic energy may in the future supplement the power that now comes from coal, oil, and falling water, but at present it cannot be produced on a basis to compete with them commercially. Before that comes there must be a long period of intensive research.
“It has never been the habit of the scientists of this country or the policy of this Government to withhold from the world scientific knowledge. Normally, therefore, everything about the work with atomic energy would be made public.
“But under present circumstances it is not intended to divulge the technical processes of production or all the military applications, pending further examination of possible methods of protecting us and the rest of the world from the danger of sudden destruction.
“I shall recommend that the Congress of the United States consider promptly the establishment of an appropriate commission to control the production and use of atomic power within the United States.
“I shall give further consideration and make further recommendations to the Congress as to how atomic power can become a powerful and forceful influence towards the maintenance of world peace.”
Still no surrender offer came. An order was issued to General Spaatz to continue operations as planned unless otherwise instructed.
On the afternoon of August 7, the U.S.S. Augusta completed a record run from Europe and entered Chesapeake Bay. As soon as the ship was moored alongside the dock at Newport News, I disembarked and entered a special train which left immediately for Washington. By 11:00 p.m., I was back at the White House, where other members of the Cabinet were on hand to greet me and to welcome me back home. It had been a month since I left the White House, and I had traveled a total of 9,346 miles.
The Russian-Chinese negotiations were resumed shortly after the Potsdam conference, when Stalin returned to Moscow. Prime Minister Soong, accompanied by the new Chinese Foreign Minister, Wang Shih-chieh, bringing further instructions from Chiang Kai-shek, went back to the Russian capital from Chungking.
Ambassador Harriman, who also had returned to his post in Moscow, was kept fully informed by Soong on the details of the talks and continued to report to me. Some of the messages had reached me on the Augusta.
On August 5, I instructed Secretary Byrnes, aboard the Augusta, to send new directions to Ambassador Harriman. I asked that Harriman tell Stalin that we believed Soong had already met the Yalta requirements. And we would request that no agreement be made involving further concessions by China, Harriman was advised through Byrnes, that might adversely affect our interests, “particularly with reference to the inclusion of the Port of Dairen in the Soviet military zone, without consultation with us. It should be recalled that President Roosevelt declined to agree to Soviet original proposal for a lease of Dairen and insisted on its internationalization as a free port. Because of our interest in the open door policy we would be opposed to the inclusion of the Port of Dairen in the Soviet military zone or its use as a Soviet naval base.”
I was not too hopeful about the renewed talks between Soong and Stalin. Ambassador Hurley, in Chungking, reported that the Russians had added a new demand that China should agree not to fortify any islands for 100 miles south of Port Arthur. The Chinese were determined to reject this new demand. On the other hand, Chiang Kai-shek had authorized Soong to agree to the inclusion, in the Soviet military zone around Port Arthur, of the area that had once been leased by the czarist Russian government, although he still insisted that Dairen and the connecting railroad be exempted.
Stalin accepted this formula and also agreed to the face-saving device of a Chinese-Russian military commission to supervise the port at Port Arthur, although the administration of the city and the port would be in the hands of the Russians. He insisted, however, that Dairen also had to be under a mixed commission, with a Soviet official in charge of the operation of the port, and at the first conference that followed Soong’s return to Moscow, Stalin also introduced a topic that had not been brought up before.
“Stalin then raised the question of ‘war trophies,’” Harriman reported, “and indicated that some of the Japanese properties, including the shares of some Japanese enterprises, should be considered as Soviet war trophies in areas occupied by the Red Army. Soong inquired exactly what Stalin had in mind, but Stalin was evasive and left the matter for future discussion. This was the first time this subject has been mentioned to Soong, and it has never been raised with us. If the Soviets define war trophies as they did in connection with Germany, including also shares of Japanese enterprises, it would be possible for the Soviets to strip Manchuria of certain of its industries and to obtain permanently complete industrial domination of Manchuria. I understand the Japanese have taken possession of, and developed most of the heavy and light industries in Manchuria. I request urgent instructions as to our position on this question, particularly if Stalin should raise the matter with me. This is another case where Stalin has increased his appetite, and I recommend that we resist his demands for shares of stock of Japanese enterprises and restrict the definition of war booty to materiel that has been historically so regarded in accordance with the United States’ definition submitted at Potsdam. As to reparations, I recommend that our position should be that all Japanese property, whether in Manchuria or elsewhere, should be available to all countries who have suffered damage by Japanese aggression to be allocated by agreement between the powers. As this subject has now been raised, I am fearful that unless we make our position plain at this time the Soviets will contend that they have the right to define unilaterally war trophies within the areas occupied by the Red Army. I have consulted Ambassador Pauley, and he concurs in these recommendations. . . .”
I was keeping a close watch on the Russian-Chinese negotiations. It was our hope that despite the long-drawn-out negotiations our two wartime allies might reach agreement. Stalin had said that Russia would not come into the war against Japan until she had concluded an agreement with China. It was for this reason that I urged Chiang Kai-shek to continue the talks in Moscow.
Without warning, while Russian-Chinese negotiations were still far from agreement, Molotov sent for Ambassador Harriman on August 8 and announced to him that the Soviet Union would consider itself at war with Japan as of August 9. This move did not surprise us. Our dropping of the atomic bomb on Japan had forced Russia to reconsider her position in the Far East. The message from Harriman informing me of this sudden switch by the Russians reached me early in the afternoon of August 8, and I promptly called a special press conference. Admiral Leahy and Secretary Byrnes were present when I met the correspondents. There were only four sentences to my announcement:
“I have only a simple announcement to make. I can’t hold a regular press conference today, but this announcement is so important I thought I would like to call you in. Russia has declared war on Japan. That is all.”
The following day, Harriman reported further on the Russian decision:
“When Molotov informed the British ambassador and me last evening that the Soviet Union would consider itself in a state of war with Japan as of August 9 he emphasized that although at one time it was thought that this action could not take place until mid-August the Soviet Government had now strictly lived up to its promise to enter Pacific War 3 months after the defeat of Germany. In reply to an inquiry made by the British ambassador as to how the Japanese ambassador had reacted to the statement handed him at 5 o’clock, Molotov first explained that Saito was a ‘kind hearted man’ and that he had always had good relations with him. Molotov continued that Saito inquired as to what the Soviet statement meant with respect to the words ‘to deliver the people from further sacrifices and suffering and to enable the Japanese people to avoid those dangers and destruction which Germany had undergone.’ Molotov replied that the Soviet Government wished to shorten the duration of the war and decrease sacrifices. Saito then remarked that the Pacific war would not be of long duration.”
In another message, Harriman reported that the Russians were not wasting any time in bringing their forces into action.
“I saw Stalin and Molotov this evening,” this second message read. “Stalin said that his advance troops had already crossed the frontiers of Manchuria both from the west and the east not meeting heavy resistance on any front and had advanced 10 or 12 kilometers in some sections. The main forces were starting across the frontier as we spoke. He said that there were 3 main attacks from the west, one south towards Heilar, the second east from Outer Mongolia towards Solun, and the third, a cavalry column, through the Gobi desert toward South Manchuria. In the Vladivostok area there was one drive west toward Grodekovo. He explained that his objectives from all directions were Harbin and Changchun. He said that his forces from the north in the Khabarovsk area were being held to attack when the enemy has been compelled to weaken their forces defending that front. He said further that they had not yet attacked in Sakhalin but were prepared to do so later. In discussing the Japanese situation he said that he thought the Japanese were looking for a pretext to set up a government that would surrender and he thought that the atomic bomb might give this pretext. He showed great interest in the atomic bomb and said that it could mean the end of war and aggression but that the secret would have to be well kept. He said that they had found in Berlin laboratories in which the Germans were working on the breaking of the atom but that he did not find that they had come to any results, Soviet scientists had also been working on the problem but had not been able to solve it.”
On August 9, the second atom bomb was dropped, this time on Nagasaki. We gave the Japanese three days in which to make up their minds to surrender, and the bombing would have been held off another two days had weather permitted. During those three days, we indicated that we meant business. On August 7, the 20th Air Force sent out a bomber force of some 130 B-29’s, and on the eighth, it reported 420 B-29’s in day and night attacks. The choice of targets for the second atom bomb was first Kokura, with Nagasaki second. The third city on the list, Niigata, had been ruled out as too distant. By the time Kokura was reached, the weather had closed in, and after three runs over the spot without a glimpse of the target, with gas running short, a try was made for the second choice, Nagasaki. There, too, the weather had closed in, but an opening in the clouds gave the bombardier his chance, and Nagasaki was successfully bombed.
This second demonstration of the power of the atomic bomb apparently threw Tokyo into a panic, for the next morning brought the first indication that the Japanese Empire was ready to surrender.