Selected Documents on Truman’s Decision to Use the Atomic Bomb, 1945

From the Harry S. Truman Presidential Library (http://www.trumanlibrary.org)

Notes of the Interim Committee Meeting, 31 May 1945: http://www.trumanlibrary.org/whistlestop/study_collections/bomb/large/documents/fulltext.php?fulltextid=7

VII. EFFECT OF THE BOMBING ON THE JAPANESE AND THEIR WILL TO FIGHT:

It was pointed out that one atomic bomb on an arsenal would not be much different from the effect caused by any Air Corps strike of present dimensions. However, Dr. [Robert] Oppenheimer [lead scientist on the atomic bomb project] stated that the visual effect of an atomic bombing would be tremendous. It would be accompanied by a brilliant luminescence which would rise to a height of 10,000 to 20,000 feet. The neutron effect of the explosion would be dangerous to life for a radius of at least two-thirds of a mile.

After much discussion concerning various types of targets and the effects to be produced, the Secretary [i.e., Secretary of War Henry Stimson] expressed the conclusion, on which there was general agreement, that we could not give the Japanese any warning; that we could not concentrate on a civilian area; but that we should seek to make a profound psychological impression on as many of the inhabitants as possible. At the suggestion of Dr. [James B.] Conant [Director of the National Defense Research Committee] the Secretary agreed that the most desirable target would be a vital war plant employing a large number of workers and closely surrounded by workers’ houses.

There was some discussion of the desirability of attempting several strikes at the same time. Dr. Oppenheimer’s judgment was that several strikes would be feasible. General [Leslie R.] Groves [military director of the project], however, expressed doubt about this proposal and pointed out the following objections: (1) We would lose the advantage of gaining additional knowledge concerning the weapon at each successive bombing; (2) such a program would require a rush job on the part of those assembling the bombs and might, therefore, be ineffective; (3) the effect would not be sufficiently distinct from our regular Air Force bombing program.

Minutes of Meeting Held at the White House, 18 June 1945: http://www.trumanlibrary.org/whistlestop/study_collections/bomb/large/documents/fulltext.php?fulltextid=1

THE PRESIDENT stated that he had called the meeting for the purpose of informing himself with respect to the details of the campaign against Japan....

General MacArthur and Admiral Nimitz are in agreement with the Chiefs of Staff in selecting 1 November as the target date to go into Kyushu because by that time:

a. If we press preparations we can be ready.

b. Our estimates are that our air action will have smashed practically every industrial target worth hitting in Japan as well as destroying huge areas in the Jap cities.

c. The Japanese Navy, if any still exists, will be completely powerless.

d. Our sea action and air power will have cut Jap reinforcement capabilities from the mainland to negligible proportions.

Important considerations bearing on the 1 November date rather than a later one are the weather and cutting to a minimum Jap time for preparation of defenses. If we delay much after the beginning of November the weather situation in the succeeding months may be such that the invasion of Japan, and hence the end of the war, will be delayed for up to 6 months....

ADMIRAL LEAHY recalled that the President had been interested in knowing what the price in casualties for Kyushu would be and whether or not that price in casualties for Kyushu would be and whether or not that price could be paid. He pointed out that the troops on Okinawa had lost 35 percent in casualties. If this percentage were applied to the number of troops to be employed in Kyushu, he thought from the similarity of the fighting to be expected that this would give a good estimate of the casualties to be expected. He was interested therefore in finding out how many troops are to be used in Kyushu.

ADMIRAL KING called attention to what he considered an important difference in Okinawa and Kyushu. There had been only one way to go on Okinawa. This meant a straight frontal attack against a highly fortified position. On Kyushu, however, landings would be made on three fronts simultaneously and there would be much more room for maneuver. It was his opinion that a realistic casualty figure for Kyushu would lie somewhere between the number experienced by General MacArthur in the operations on Luzon and the Okinawa casualties.

GENERAL MARSHALL pointed out that the total assault troops for the Kyushu campaign were shown in the memorandum prepared for the President as 766,700. He said, in answer to the President’s question as to what opposition could be expected on Kyushu, that it was estimated at eight Japanese divisions or about 350,000 troops. He said that divisions were still being raised in Japan and that reinforcement from other areas was possible but it was becoming increasingly difficult and painful....

THE PRESIDENT said that as he understood it the Joint Chiefs of Staff, after weighing all the possibilities of the situation and considering all possible alternative plans, were still of the unanimous opinion that the Kyushu operation was the best solution under the circumstances.

The Chiefs of Staff agreed that this was so.

THE PRESIDENT then asked the Secretary of War for his opinion.

MR. STIMSON agreed with the Chiefs of Staff that there was no other choice. He felt that he was personally responsible to the President more for political than for Military considerations. It was his opinion that there was a large submerged class in Japan who do not favor the present war and whose full opinion and influence had never yet been felt. He felt sure that this submerged class would fight and fight tenaciously if attacked on their own ground. He was concerned that something should be done to arouse them and to develop any possible influence they might have before it became necessary to come to grips with them.

THE PRESIDENT stated that this possibility was being worked on all the time. He asked if the invasion of Japan by white men would not have the effect of more closely uniting the Japanese.

MR.STIMSON thought there was every prospect of this. He agreed with the plan proposed by the Joint Chiefs of Staff as being the best thing to do, but he still hoped for some fruitful accomplishment through other means....

Notes of the Interim Committee Meeting, 21 June 1945: http://www.trumanlibrary.org/whistlestop/study_collections/bomb/large/documents/fulltext.php?fulltextid=11

b. Immediate use of the weapon.

Mr.[George L.] Harrison [chairman of the committee] explained that he had recently received through Dr. A. H. Compton a report from a group of the scientists at Chicago recommending, among other things, that the weapon not be used in this war but that a purely technical test be conducted which would be made known to other countries. Mr. Harrison had turned this report over to the Scientific Panel for study and recommendation. Part II of the report of the Scientific Panel stated that they saw no acceptable alternative to direct military use. The Committee reaffirmed the position taken at the 31 May and 1 June meetings that the weapon be used against Japan at the earliest opportunity, that it be used without warning, and that it be used on a dual target, namely, a military installation or war plant surrounded by or adjacent to homes or other buildings most susceptible to damage.

Pages from President Truman’s Diary: http://www.trumanlibrary.org/whistlestop/study_collections/bomb/large/documents/fulltext.php?fulltextid=15

July 19, 1945

....P.M. [Winston Churchill] and I ate alone. Discussed Manhattan [the atomic bomb project] (it is a success). Decided to tell Stalin about it. Stalin had told P.M. of telegram from Jap Emperor asking for peace. Stalin also read his answer to me. It was satisfactory. Believe Japs will fold up before Russia comes in.

I am sure they will when Manhattan appears over their homeland.

July 25, 1945

We have discovered the most terrible bomb in the history of the world. It may be the fire distruction [destruction] prophesied in the Euphrates Valley Era, after Noah and his fabulous Ark. Anyway we think we have found the way to cause a disintegration of the atom. An experiment in the New Mexican desert was startling—to put it mildly. Thirteen pounds of the explosive caused the complete disintegration of a steel tower 60 feet high, created a crater 6 feet deep and 1200 feet in diameter, knocked over a steel tower 1/2 mile away and knocked men down 10,000 yards away. The explosion was visible for more than 200 miles and audible for 40 miles and more.

This weapon is to be used against Japan between now and August 10th. I have told the Sec. of War, Mr. Stimson to use it so that military objectives and soldiers and sailors are the target and not women and children....

He and I are in accord. The target will be a purely military one and we will issue a warning statement asking the Japs to surrender and save lives. I'm sure they will not do that, but we will have given them the chance. It is certainly a good thing for the world that Hitler's crowd or Stalin's did not discover this atomic bomb. It seems to be the most terrible thing ever discovered, but it can be made the most useful.

Memorandum for General Arnold: http://www.trumanlibrary.org/whistlestop/study_collections/bomb/large/documents/fulltext.php?fulltextid=18

SUBJECT: Groves Project

1. The following plan and schedule for initial attacks using special bombs have been worked out:

a. The first bomb (gun type) will be ready to drop between August 1 and 10 and plans are to drop it the first day of good weather following readiness.

b. The following targets have been selected: Hiroshima, Kokura, Niigata and Nagasaki.

(1) Hiroshima (population 350,000) is an "Army" city; a major POE [port of embarkation]; has large QM [quartermaster] and supply depots; has considerable industry and several small shipyards.

(2) Nagasaki (population 210,000) is a major shipping and industrial center of Kyushu.

(3) Kokura (population 178,000) has one of the largest army arsenals and ordnance works; has the largest railroad shops on Kyushu: and has large munitions storage to the south.

(4) Niigata (population 150,000) is an important industrial city, building machine tools, diesel engines, etc., and is a key port for shipping to the mainland.

c. All four cities are believed to contain large numbers of key Japanese industrialists and political figures who have sought refuge from major destroyed cities.

d. The attack is planned to be visual to insure accuracy and will await favorable weather. The four targets give a very high probability of one being open even if the weather varies from that forecast, as they are considerably separated....

2. Two tested type bombs are expected to be available in August, one about the 6th and another the 24th. General Groves expects to have more information on future availabilities in a few days which will be furnished you when received.

3. The above has been discussed with Generals Spaatz and Eaker who concur.

JOHN N. STONE
Colonel, GSC

Statement by the President of the United States, August 6, 1945: http://www.trumanlibrary.org/whistlestop/study_collections/bomb/large/documents/index.php?documentdate=1945-08-06&documentid=56&studycollectionid=abomb&pagenumber=1

Sixteen hours ago an American airplane dropped one bomb on [the city of Hiroshima] and destroyed its usefulness to the enemy. That bomb had more power than 20,000 tons of T.N.T. It had more than two thousand times the blast power of the British “Grand Slam” which is the largest bomb ever yet used in the history of warfare.

The Japanese began the war from the air at Pearl Harbor. They have been repaid many fold. And the end is not yet. With this bomb we have now added a new and revolutionary increase in destruction to supplement the growing power of our armed forces. In their present form these bombs are now in production and even more powerful forms are in development.

It is an atomic bomb. It is a harnessing of the basic power of the universe. The force from which the sun draws its power has been loosed against those who brought war to the Far East....

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....

Translation of a leaflet dropped on Japanese cities shortly after the first atomic bomb was dropped, 6 August 1945: http://www.trumanlibrary.org/whistlestop/study_collections/bomb/large/documents/index.php?documentdate=1945-08-06&documentid=7&studycollectionid=abomb&pagenumber=1

TO THE JAPANESE PEOPLE:

America asks that you take immediate heed of what we say on this leaflet.

We are in possession of the most destructive explosive ever devised by man. A single one of our newly developed atomic bombs is actually the equivalent in explosive power to what 2000 of our giant B-29’s can carry on a single mission. This awful fact is one for you to ponder and we solemnly assure you it is grimly accurate.

We have just begun to use this weapon against your homeland. If you still have any doubt, make inquiry as to what happened in Hiroshima when just one atomic bomb fell on that city.

Before using this bomb to destroy every resource of the military by which they are prolonging this useless war, we ask that you now petition the Emperor to end the war. Our President has outlined for you the thirteen consequences of an honorable surrender: We urge that you accept those consequences and begin the work of building a new, better, and peace-loving Japan.

You should take steps now to cease military resistance. Otherwise, we shall resolutely employ this bomb and all our other superior weapons to promptly and forcefully end the war.

EVACUATE YOUR CITIES!