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President Truman: Using Atomic Bombs against Japan, 1945

Digital History TOPIC ID 63

Every American president makes decisions with enormous repercussions for the future. Some of these decisions prove successful; others turn out to be blunders. In virtually every case, presidents must act with contradictory advice and limited information. At 8:15 a.m., August 6, 1945, an American B-29 released an atomic bomb over Hiroshima, Japan. Within minutes, Japan’s eighth largest city was destroyed. By the end of the year, 140,000 people had died from the bomb’s effects. After the bombing was completed, the United States announced that Japan faced a rain of ruin from the air, the like of which had never been seen on this earth." Background: In 1939, Albert Einstein, writing on behalf physicist Leo Szilard and other leading physicists, informed President Franklin D. Roosevelt that Nazi Germany was carrying on experiments in the use of atomic weapons. In October, 1939, the federal government began a modest research program which and later became the two-billion-dollar Manhattan Project. Its purpose was to produce an atomic bomb before the Germans. On December 2, 1942, scientists in Chicago succeeded in starting a nuclear chain reaction, demonstrating the possibility of unleashing atomic power.

It was not until April 25, 1945, 13 days after the death of Franklin Roosevelt, that the new president, Harry S. Truman, was briefed about the Manhattan Project. Secretary of War Henry Stimson informed him that "within four months we shall in all probability have completed the most terrible weapon ever known in human history."

Stimson proposed that a special committee be set up to consider whether the atomic bomb would be used, and if so, when and where it would be deployed. Members of this panel, known as the Interim Committee, which Stimson chaired, included George L. Harrison, President of the New York Life Insurance Company and special consultant in the Secretary's office; James F. Byrnes, President Truman's personal representative; Ralph A. Bard, Under Secretary of the Navy; William L. Clayton, Assistant Secretary of State; and scientific advisers Vannevar Bush, Karl T. Compton, and James B. Conant. General George Marshall and Manhattan Project Director Leslie Groves also participated in some of the committee’s meetings. On June 1, 1945, the Interim Committee recommended that that atomic bombs should be dropped on military targets in Japan as soon as possible and without warning. One committee member, Ralph Bard, convinced that Japan may be seeking a way to end the war, called for a two to three day warning before the bomb was dropped.

A group of scientists involved in the Manhattan project opposed the use of the atomic bomb as a military weapon. In a report signed by physicist James Franck, they called for a public demonstration of the weapon in a desert or on a barren island. On June 16, 1945, a scientific panel consisting of physicists Arthur H. Compton, Enrico Fermi, E. O. Lawrence, and J. Robert Oppenheimer reported that it did not believe that a technical demonstration would be sufficient to end the war.

Meanwhile, after a June 18, 1945, meeting with his military advisors, President Truman approved a plan that called for an initial invasion of Japan on November 1. By the summer of 1945, a growing number of government policy makers were concerned about Soviet intervention in the war against Japan. Already, the Red Army occupied Rumania, Bulgaria, Yugoslavia, Czechoslovakia, and Hungary. At the Potsdam conference in July, Soviet Premier Joseph Stalin informed President Truman and British Prime Minister Winston Churchill that the Red Army would enter the war against Japan around August 8. On July 25, 1945, the military was authorized to drop the bomb as soon as weather will permit visual bombing after about 3 August 1945 on one of the targets: Hiroshima, Kokura, Niigata and Nagasaki." The bombing of Hiroshima, followed by the Soviet declaration of war against Japan on August 9th and the bombing of Nagasaki the same day, led the Japanese leadership to accept a surrender so long as their country could retain the emperor. Variety of points of view:

  1. Ralph Bard, Under Secretary of the Navy: Ever since I have been in touch with this program I have had a feeling that before the bomb is actually used against Japan that Japan should have some preliminary warning for say two or three days in advance of use. The position of the United States as a great humanitarian nation and the fair play attitude of our people generally is responsible in the main for this feeling.
  2. James Byrnes: [Physicist Leo Szilard wrote:] "[Byrnes] was concerned about Russia's postwar behavior. Russian troops had moved into Hungary and Rumania, and Byrnes thought it would be very difficult to persuade Russia to withdraw her troops from these countries, that Russia might be more manageable if impressed by American military might, and that a demonstration of the bomb might impress Russia."
  3. General Dwight D. Eisenhower: "In 1945 ... , Secretary of War Stimson visited my headquarters in Germany, [and] informed me that our government was preparing to drop an atomic bomb on Japan. I was one of those who felt that there were a number of cogent reasons to question the wisdom of such an act.... During his recitation of the relevant facts, I had been conscious of a feeling of depression and so I voiced to him my grave misgivings, first on the basis of my belief that Japan was already defeated and that dropping the bomb was completely unnecessary, and second because I thought that our country should avoid shocking world opinion by the use of a weapon whose employment was, I thought, no longer mandatory as a measure to save American lives. It was my belief that Japan was, at that very moment, seeking some way to surrender with a minimum loss of 'face.'
Admiral William Leahy told President Truman: "This is the biggest fool thing we have ever done. The bomb will never go off, and I speak as an expert in explosives."

What consequences did the use of atomic weapons have on the American public?

Questions to Think About:

1. Was Japan on the verge of surrender in August 1945?

2. What factors did the decision makers take into account when they evaluated the use of the atomic bombs?

3. Why did the United States and its allies inform the Japanese that their country could retain the emperor before the atomic bombs were dropped?

4. To what extent was the timing of the use of the bombs related to Soviet intervention in the war against Japan?

5. Identify each of the following and compare and contrast their views about the decision to deploy the bomb:

  • Henry Arnold Leslie R. Groves
  • Ralph Bard William Leahy
  • James F. Byrnes George C. Marshall
  • Arthur Holly Compton
  • J. Robert Oppenheimer
  • James B. Conant Henry L. Stimson
  • Dwight D. Eisenhower
  • Leo Szilard
  • James Franck
  • Edward Teller
Primary Sources:

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