Diary Note of President Harry S. Truman

In this diary entry, President Truman discusses the Trinity test of the atomic bomb in New Mexico.  He describes the destructive power of the new weapon and the intention on using it against a Japanese military target in the upcoming weeks. Truman also describes the meeting with Winston Churchill and Joseph Stalin as part of the Potsdam Conference.

Transcript

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 Montbatten & General Marshall before that. 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 disintregation 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. Even if the Japs are savages, ruthless, merciless and fanatic, we as the leader of the world for the common welfare cannot drop this terrible bomb on the old Capitol or the new.

He & 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 Hitlers 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.

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At 10:15 I had Gen Marshall come in and discuss with me the tactical and political situation. He is a level headed man -- so is Montbatton.

At the Conference Poland and the Bolshiviki land grab came up. Russia helped herself to a slice of Poland and gave Poland a nice slice of Germany taking also a good slice of East Prussia for herself. Poland has moved in up to the Oder and the west Niesse, taking Stettin and Silesia as a fait accomplished. My position is that according to commitments made at Yalta by my predecessor Germany was to be divided into four occupation zones, one each for Britain, Russia and France and the U.S. If Russia chooses to allow Poland to occupy a part of her zone. I am agreeable but title to territory cannot and will not be settled here. For the fourth time I restated my position and explained that territorial sessions had to be made by treaty and ratified by the Senate.

We discussed reparations and movement of populations from East Germany, Czekoslavokia, Austria, Italy and elsewhere. Churchill said Maisky had so defined war booty as to includ the [scratched out] German fleet and Merchant Marine. It was a bomb shell and sort of paralyzed the Ruskies, but it has a lot of merit.