Diary Entry: Stimson mentions the Bomb to Truman after 12 April Cabinet Meeting

That first cabinet meeting was short, and when it adjourned, the members rose silently and made their way from the room--except for Secretary Stimson. 

He asked to speak to me about a most urgent matter. Stimson told me that he wanted me to know about an immense project that was underway--a project looking to the development of a new explosive of almost unbelievable destructive power. That was all he felt free to say at the time, and his statement left me puzzled. It was the first bit of information that had come to me about the atomic bomb, but he gave me no details.... The next day Jimmy Byrnes, who until shortly before had been Director of War Mobilization for President Roosevelt, came to see me, and even he told me a few details, though with great solemnity he said that we were perfecting an explosive great enough to destroy the whole world.

Source: Memoirs by Harry S. Truman, 1945: Year of Decisions (New York: Smithmark, 1995), pp. 10-11. 

Truman's Diary Entry April 12 1945

I did not know what effect the situation [the change in Presidents] would have on the war effort, price control, war production and everything that entered into the emergency that then existed. I knew the President had a great many meetings with Churchill and Stalin. I was not familiar with any of these things and it was really something to think about but I decided the best thing to do was to go home and get as much rest as possible and face the music.

President Franklin Roosevelt dies. Vice-President Harry Truman becomes President.

Truman Diary Entry June 17, 1945

I have to decide Japanese strategy - shall we invade Japan proper or shall we bomb and blockade? That is my hardest decision to date. But I'll make it when I have all the facts.

The next day Truman met with military representatives to discuss how the war against Japan should proceed. Truman decided at that meeting to have the Joint Chiefs of Staff go ahead with plans to invade Kyushu, the southernmost of Japan's four major islands. The planned invasion date was Nov. 1, 1945.

Truman Diary Entry, June 18 1945

At the meeting of June 18, '45 the invasion plan for Japan was discussed. General Marshall's plan was approved.
We were approaching an experiment with the atom explosion. I was informed that event would take place within a possible thirty days.

I then suggested that after that experimental test of the fission of the atom, that we give Japan a chance to stop the war by a surrender. That plan was followed. Japan refused to surrender and the bomb was dropped on two targets after which event the surrender took place.

Following the decision referred to in the last memo, when the message arrived informing us of the successful explosion of the experimental atom bomb at Los Alamos, Sec. Stimson, Gen. Marshall, Adm. Leahy, Sec. Byrnes, Gen Arnold and one or two others came into my office at the Potsdam White House and we discussed the proposed ultimatum talked about on June 18th.

After some discussion it was decided to send the message from Potsdam. Of course Chiang had to be informed and asked to join with Pr. Min. Churchill and myself. The message was sent both by air and through Sweden and Switzerland I'm sure. We had nothing in reply but the radio statement refusing to surrender.

I am not informed at all on the last question. It is probably a Monday morning quarterback affair after the game was over.
H.S.T.

Truman Diary Entry, July 17 1945

Just spent a couple of hours with Stalin. Joe Denis called on Maiski and made the date last night for noon today. Promptly a few minutes before twelve I looked up from the desk and there stood Stalin in the doorway. I got to my feet and advanced to meet him. He put out his hand and smiled. I did the same, we shook, I greeted Molotov and the interpreter and we sat down. After the usual polite remarks we got down to business. I told Stalin that I am no diplomat but usually said yes or no to questions after hearing all the argument. It pleased him. I asked him if he had the agenda for the meeting. He said he had some more questions to present. I told him to fire away. He did and it is dynamite--but I have some dynamite too which I'm not exploding now.

He wants to fire Fianco, to which I wouldn't object and divide up the Italian colonies and other mandates, some no doubt that the British have Then he got on the Chinese situation told us what agreements had been reached and what was in abeyance. Most of the big points are settled. He'll be in the Jap War on August 15th. Fini Japs when that comes about. We had lunch, talked socially, put on a real sham drinking toasts to everyone, then had pictures made in the back yard. I can deal with Stalin. He is honest--but smart as hell.

Truman Diary Entry, July 18 1945

Ate breakfast with nephew Harry, a sergeant in the Field Artillery. He is a good soldier and a nice boy. They took him off Queen Elizabeth at Glasco and flew him here. Sending him home Friday. Went to lunch with P.M., at 1:30 walked around to British Hqrs. Met at the gate by Mr. Churchill. Guard of honor drawn up. Fine body of men Scottish Guards. Band played Star Spangled Banner. Inspected Guard and went in for lunch. P.M. and I ate alone. Discussed Manhattan (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. I shall inform Stalin about it at an opportune time.

Stalin's luncheon was a most satisfactory meeting. I invited him to come to the U.S. Told him I'd send the Battleship Missouri for him if he'd come. He said he wanted to cooperate with U.S. in peace as we had cooperated in war but it would be harder. Said he was grossly misunderstood in U.S. and I was misunderstood in Russia. I told him that we each could help to remedy that situation in our home countries and that I intended to try with all I had to do my part at home. He gave me a most cordial smile and said he would do as much in Russia.We then went to the conference and it was my job to present the Ministers proposed agenda. There were three proposals and I banged them through in short order, much to the surprise of Mr. Churchill. Stalin was very much pleased. Churchill was too after he had recovered. I’m not going to stay around this terrible place all Sunday just to listen to speeches. I’ll go home to the Senate for that.

Truman Diary Entry, July 19 1945

Stalin was a day late in arriving. It was reported that he was not feeling up to par. He called on me as soon as he arrived. It was about 11 A.M. He, Molotov, Vishinski and Pavlov stayed for lunch. We had a most pleasant conference and Stalin assured me that Russia intended to carry out the Yalta agreements and to enter the war against Japan in August.

This entry appears to refer to the meeting between Truman and Stalin on 7/17/45 at the Potsdam Conference. It may have been written by Truman in the Fall of 1951 for his aide Eben Ayers.

Truman Diary Entry, July 20 1945

Jim Blair now Lt. Col. came in for breakfast. Harry left for Paris & N.Y. Sure hated to see him go. Discussed German situation with Jim. He had been in command of clean up detail which prepared the area for American occupation especially for our conference delegation. Said it was the filthiest place imaginable. No sanitary arrangement whatever. Toilets all full and all stopped up. Basements used as outdoor toilets. Said the sewer system evidently hadn't worked for months. Same all over town. Said Germans are sore and sullen. That we would not treat them rough enough. Russians treated 'em too rough and too kindly. Anyway its a hell of a mess any way it's taken.

Saw Gen. Omar Bradley about taking over the Vets. bureau. Will take over Aug. 15th. Talked to Gen. Eisenhower about government of Germany along same lines as I'd talked to Gen. Clay. Got a concrete program to present.

Raised a flag over our area in Berlin. It is the flag raised in Rome, North Africa and Paris. Flag was on the White House when Pearl Harbor happened. Well be raised over Tokyo.

Uncle Joe looked drawn and tired today and the P.M. seemed lost. I told 'em U.S. had ceased to give away it's assets without returns.

Truman Diary Entry, July 25 1945

We met at 11 A.M. today. That is Stalin, Churchill and the U.S. President. But I had a most important session with Lord Mountbattan & General Marshall before than. We have discovered the most terrible bomb in the history of the world. It may be the fire 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 1,200 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.

Privately, Truman later expressed misgivings about the mass killing of civilians in Hiroshima; see the "Didn't the Japanese Deserve It?" section in Random Ramblings on Hiroshima.

7/25/45: Sec. of War Henry Stimson and Army Chief of Staff George Marshall approved and sent the order to drop atomic bombs on Japan 

Truman Diary Entry, July 30 1945

Sent Capt. Vardaman to ship at Portsmouth, Eng. to get ready for departure to US some day soon. Secretary of Navy Joe Forestal came to breakfast with me and we discussed universal military service after the war and navy policy on office training etc.Gen. Eisenhower and son were also at breakfast with us. His boy is a nice fellow. Adm. Cochran and several other naval officers were present.

Conference is delayed. Stalin and Molotov were to call on me yesterday to discuss Polish question and Reparations. Molotov came but no Stalin. Said he is sick. No big three meeting yesterday and none today as a result of Stalins indisposition. Send him a note expressing regret at his illness. Sent Churchill a note of consolation, telling him we regreted his failure to return and wishing him a long and happy life.

If Stalin should suddenly cash in it would end the original Big Three. First Roosevelt by death, then Churchill by political failure and the Stalin. I am wondering what would happen to Russia and central Europe if Joe suddenly passed out. If some demagogue on horse back gained control of the efficient Russian military machine he could play havoc with European peace for a while. I also wonder if there is a man with the necessary strength and following to step into Stalin's place and maintain peace and solidarity at home. It isn't customary for dictators to train leaders to follow them in power. I've seen no one at this Conference in the Russian line up who can do the job. Molotov is not able to do it. He lacks sincerity. Vishinsky same thing and Maisky is short on honesty. Well we shall see what we shall see. Uncle Joe's pretty tough mentally and physically but there is an end to every man and we can't help but speculate.

We are at an impass on Poland and its western boundary and on Reparations Russia and Poland have agreed on the Oder and West Niesse to the Czechoslovakian border. Just a unilateral arrangement without so much a by your lease. I don't like it. Roosevelt let Maisky mention twenty billions as reparations -- half for Russia and half for everybody else. Experts say no such figure is available. I've made it plain that the United States of America does not intend to pay reparations this time. I want the German war industry machine completely dismantled and far as U.S. is concerned the other allies can divide it up on any basis they choose. 

Food and other necessities we send into the restored countries and Germany must be first lein on export before reparation. If Russian strip country and carry off population of course there'll be no reparations.

I have offered a waterway program and a suggestion for free intercourse between Central European nations which will help keep future peace. Our only hope for good from the European War is restored prosperity to Europe and future trade with them. It is a sick situation at best.

Truman Diary Entry, August 10 1945

Ate lunch at my desk and discussed the Jap offer to surrender which came in a couple of hours earlier. They wanted to make a condition precedent to the surrender. Our terms are 'unconditional'. They wanted to keep the Emperor. We told 'em we'd tell 'em how to keep him, but we'd make the terms.

8/10/45: Having received reports and photographs of the effects of the Hiroshima bomb, Truman ordered a halt to further atomic bombings. Sec. of Commerce Henry Wallace recorded in his diary on the 10th, Truman said he had given orders to stop atomic bombing. He said the thought of wiping out another 100,000 people was too horrible. He didn't like the idea of killing, as he said, 'all those kids'.

Truman Diary Entry, August 11 1945

We are all on edge waiting for the Japs to answer. Have had a hell of a day.