Harry Truman and The Bomb

Today’s post is from Lee Lacy, an Assistant Professor at the U.S. Army Command & General Staff College, Fort Leavenworth, Kansas. 

When Harry S. Truman was told on April 12, 1945, by Eleanor Roosevelt that her husband, President Franklin D. Roosevelt, was dead, Truman reacted true to form.

Henry Stimson to Harry S. Truman, April 24, 1945. (Harry S. Truman Presidential Library)
Henry Stimson to Harry S. Truman, April 24, 1945. (Harry S. Truman Presidential Library)

He asked if there was anything he could do. Her famous reply: “Is there anything we can do for you? For you are the one in trouble now.”

Trouble indeed. Truman would soon learn just how much FDR did not tell him about the status of the war effort.

Moments after Truman’s hastily-called swearing in ceremony, Secretary of War Henry Stimson lingered to speak with him about an “immense project.” Stimson briefly told Truman about the Manhattan Project, but Truman deferred an in-depth discussion to a later date.

The nation was in shock over the death of FDR, the only President many Americans had ever known, and World War II raged on. Germany was close to collapse, but it appeared that the war against Japan might go to the Japanese mainland and drag out into 1946. Amidst these troubles, Truman had to learn all the things FDR did not tell his newly-elected Vice President, in office only 82 days.

The issue of the “immense project”—the atomic bomb—re-surfaced April 24 when Stimson pressed for an appointment. Truman met with him the next day. The President listened intently. He already knew some sketchy details from his days in the Senate when he discovered secret War Department spending. Stimson advised Truman to appoint a committee to study the use of atomic weapons, which Truman took under consideration.

For the moment, any decisions regarding the use of the atomic bomb were put off. Elsewhere, plans for the invasion of Kyushu, Japan’s southern-most province, proceeded in earnest. Truman remained hopeful Japan might surrender, given the great damage inflicted by strategic bombing.

Truman's handwriting on the back of a Potsdam photograph describing telling Stalin about the atomic bomb, July 19, 1945. (Harry S. Truman Presidential Library)
Truman’s handwriting on the back of a Potsdam photograph describing telling Stalin about the atomic bomb, July 19, 1945. (Harry S. Truman Presidential Library)

In May 1945, Acting Secretary of State Joseph Grew spoke to Truman about a plan to get Japan to surrender. Truman gave his support and presented it to the Joint Chiefs. The use of atomic weapons remained under consideration and no final decision was made. Truman sought the advice and opinions of others. He prepared himself and read voraciously.

As the Allied Powers prepared to meet in Potsdam, Germany, Truman wanted to release another surrender ultimatum at the meeting. He hoped the ultimatum would coincide with a successful test of the atomic bomb to demonstrate the resolve of the Allies to Japan.

Still, early in July 1945, no final decision was made about the bomb, but Truman knew it was a viable option and he continued to gather information. The committee formed to study this new weapon met and advised Truman to use it immediately—and without warning. No demonstration as a warning was recommended. Truman consulted British Prime Minister Winston Churchill, who concurred.

No doubt the weight of the world was on Truman’s shoulders, and the final decision was not easy.Finally, he concluded it was his decision, alone, if, when, and where to use the bomb. On July 24, 1945, the order was issued to U.S. Army Strategic Air Forces with operational control delegated to its commander, General Carl Spaatz.

If the recent invasion of Okinawa was any predictor, an amphibious invasion of the Japanese mainland was unthinkable. Neither were the estimated millions of American lives that would be lost if mainland Japan was invaded.

This, in part, prompted Truman to give Japan one more chance to surrender. Another warning was issued to the Japanese on July 26 from the Potsdam conference. On July 28, Japan announced its intention to continue the war. There was no alternative—Truman had to take action to end the war.

Secretary of War Henry Stimson's cable to President Truman regarding the atomic bomb, 07/30/1945. (National Archives Identifier 200665)
Secretary of War Henry Stimson’s cable to President Truman regarding the atomic bomb, 07/30/1945. (National Archives Identifier 200665)
Truman's handwritten reply to Stimson's cable, 07/30/1945. (National Archives Identifier  200665)
Truman’s handwritten reply to Stimson’s cable, 07/30/1945. (National Archives Identifier 200665)


Hiroshima and Nagasaki were bombed on August 6 and August 9, respectively, and the war came to a dramatic end a few days later.

President Truman announces Japan's surrender, August 14, 1945. (National Archives Identifier 520054)
President Truman announces Japan’s surrender, August 14, 1945. (National Archives Identifier 520054)

For his part, Truman never regretted his decision—nor did he ever gloat, even in the face of decades of second-guessing by those who disagreed with him.

Truman made the decision, and, as he was fond of saying, “that’s all there was to it.”

Professor Lacy drew this account from Truman’s memoirs and from the archives of the Truman Presidential Library in Independence, MO. Dr. Lacy can be contacted at lee.o.lacy.civ@mail.mil.

To view original documents relating to the use of the A-bomb, visit the Harry S. Truman Library & Museum’s website.

3 thoughts on “Harry Truman and The Bomb

  1. Truman may not have had any regrets, but others did. U.S. Fleet Admiral Leahy was the Chair of the Joint Chiefs in 1945. Reflecting on his Commander in Chief’s decision in his memoirs here is what he wrote: “It is my opinion that the use of this barbarous weapon at Hiroshima and Nagasaki was of no material assistance in our war against Japan. The Japanese were already defeated and ready to surrender because of the effective sea blockade and the successful bombing with conventional weapons.” (William D. Leahy, I Was There, pg. 441).

  2. Japanese surrendered only after jt was given assurance the Emperor would remain as Emperor but no power. If unconditional surrender had been dropped earlier, possibility many lives could have been saved.

  3. If Japan didn’t start a war it could not possibly win tens of millions of lives would have been saved. The war was over the day it started only Japan didn’t know how to surrender. Japan was in no position to make any demands on surrender terms. They made blunder after blunder starting with the decision to attack the United States which sealed their fate. They should have surrendered after Pearl Harbor when they failed to damage any of the United State’s aircraft carriers, drydocks ,and fuel storage. They certainly should have surrendered after Midway where 4 of their aircraft carriers were sunk in 10 minutes. What a waste.

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