5-176 Editorial Note on the Atomic Bomb

Publisher: The Johns Hopkins University Press

Subject: World War II

Editorial Note on the Atomic Bomb

July 16-30, 1945

TRINITY was the code name for the atomic bomb test site in central New Mexico where, at 3:30 A.M. on July 16, the uranium-235 fission device was successfully tested. The War Department notified Secretary of War Stimson, who received the message at 7:30 P.M. in Babelsberg, that the TRINITY test was a success. Stimson hurried to President Truman with the news. The next morning (July 17), he called Marshall and Arnold to his quarters, showed them the message, and discussed with them the bomb’s use. (July 16, 1945, Yale/H. L. Stimson Papers [Diary, 52: 23]; Arnold, Global Mission, pp. 584-85.)

Shortly before noon on July 21, a special courier brought the secretary a detailed report on the test by Major General Leslie R. Groves, head of the MANHATTAN Project. “At three o’clock,” Stimson recorded, “I found that Marshall had returned from the Joint Chiefs of Staff, and to save time I hurried to his house and had him read Groves’ report and conferred with him about it.” After reading the document, President Truman felt “tremendously pepped up.” The next day, Prime Minister Churchill was even more enthusiastic, telling the British Chiefs of Staff that the weapon would help the West redress the balance of power in Europe that seemed so favorable to the Soviet Union. (July 21, 1945, Yale/H. L. Stimson Papers [Diary, 52: 31]; Alanbrooke, War Diaries, p. 709.) Further messages from Washington indicated that two bombs would be ready for combat use by August 1. (Vincent C. Jones, MANHATTAN: The Army and the Atomic Bomb, a volume in the United States Army in World War II [Washington: GPO, 1985], pp. 234, 236.)

Did this new weapon eliminate the need for Soviet intervention in the Pacific war, the president asked of Marshall. “Of course Marshall could not answer directly or explicitly,” Stimson noted.

We had desired the Russians to come into the war originally for the sake of holding up in Manchuria the Japanese Manchurian Army. That now was being accomplished as the Russians have amassed their forces on that border, Marshall said, and were poised, and the Japanese were moving up positions in their Army. But he pointed out that even if we went ahead in the war without the Russians, and compelled the Japanese to surrender to our terms, that would not prevent the Russians from marching into Manchuria anyhow and striking, thus permitting them to get virtually what they wanted in the surrender terms. (July 23, 1945, Yale/H. L. Stimson Papers [Diary, 52: 36].)

Marshall believed that the United States did not require Soviet assistance to conquer Japan, but it would be useful in saving time and casualties. In the Combined Chiefs of Staff’s “Agreed Summary of Conclusions Reached” at Potsdam—approved by Truman and Churchill on July 24—paragraph 7a stated that the Allies should “encourage Russian entry into the war against Japan.” (This report is in Foreign Relations, Potsdam Conference, 2: 1462-73; quote on p. 1463.)

Marshall regarded using atomic bombs as necessary to shorten the war, and he never thereafter altered his belief. Extraordinarily destructive U.S. air raids on Japan and disastrous Japanese losses in the Pacific islands campaigns had not appeared to undermine Japanese morale, and U.S. planners expected the invasion of the home islands to be costly in American and Japanese lives. Marshall was aware that Japanese diplomats were extending some peace feelers, but the evidence indicated that the Imperial Japanese Army not the Foreign Ministry was in charge, and the army “could only apparently be slugged into submission”—which they would be if they ignored the Potsdam Declaration’s July 26 call for unconditional surrender. (George C. Marshall Interviews and Reminiscences for Forrest C. Pogue, 3d ed. [Lexington, Va.: George C. Marshall Foundation, 1996], pp. 424-25. The declaration or proclamation is in Foreign Relations, Potsdam Conference, 2: 1474-76.)

On July 24, Marshall received Groves’s draft directive ordering the use of the bomb. Marshall approved it; the following morning he secured Secretary Stimson’s approval and discussed it with President Truman. That same day (July 25), the message was sent from General Thomas T. Handy (acting chief of staff) to General Carl Spaatz (commanding general, U.S. Army Strategic Air Forces); the directive began: “The 509 Composite Group, 20th Air Force will deliver its first special bomb as soon as weather will permit visual bombing after about 3 August 1945 on one of the targets: Hiroshima, Kokura, Niigata and Nagasaki.” (A facsimile of this document is in Wesley Frank Craven and James Lea Cate, eds., The Pacific: MATTERHORN to Nagasaki, June 1944 to August 1945, a volume in The Army Air Forces in World War II [Chicago: University of Chicago Press, 1953], facing p. 697. President Truman told Dr. Cate in 1953 that he made the final decision on the bomb while at sea on August 2 or 3. [Ibid., p. 714.] See also Jones, MANHATTAN, p. 534.)

By July 24, with the Combined Chiefs of Staff’s conference report approved and the ultimatum to Japan nearly ready, there was little left for British and American military leaders to do, and they prepared to depart. First, however, that afternoon they held their only meeting with the Soviet chiefs of staff. Red Army leader General A. I. Antonov described preparations for an attack on Japanese forces in the Far East. Marshall followed with a comprehensive explanation of Japan’s military position in the Pacific and China. He concluded by giving Antonov a book analyzing the United States’s experiences in fighting the Japanese. Admiral King and General Arnold made brief supplemental remarks. The British Chiefs of Staff explained the military situation in Southeast Asia. (See the minutes of this meeting in Foreign Relations, Potsdam Conference, 2: 344-53.)

The Potsdam Conference took a brief hiatus between July 25 and 30. Winston Churchill and other British civilian leaders returned to London on the twenty-fifth to observe the vote counting from the recent election. The British Chiefs of Staff likewise departed that day, and Admiral Leahy flew to London to visit friends. Secretary of War Stimson left for Munich to visit General Patton before returning to the United States. General Marshall and Admiral King planned to fly separately to Salzburg, Austria, on the twenty-seventh to do some sightseeing around Hitler’s former headquarters at Berchtesgaden, Germany. Marshall and his aide, Frank McCarthy, also hoped to do some trout fishing.

Recommended Citation: ThePapers of George Catlett Marshall, ed.Larry I. Bland and Sharon Ritenour Stevens(Lexington, Va.: The George C. Marshall Foundation, 1981- ). Electronic version based on The Papers of George Catlett Marshall, vol. 5, “The Finest Soldier,” January 1, 1945-January 7, 1947 (Baltimore and London: The Johns Hopkins University Press, 2003), pp. 248-251.

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