Atomic bombing of Hiroshima, August 6, 1945

August 6, 1945, brought the first use of an atomic bomb in war into Harry S. Truman’s immediate view: while at sea, he received the initial report of the bombing of Hiroshima, then announced its success to the crew and to the country. The day joined a private moment of startling news to a public declaration of a weapon whose power was still only beginning to be understood.

Background and the decision to use the bomb

The bombing followed months of debate over how to force Japan’s surrender. Henry L. Stimson opposed allowing the United States to surpass Hitler in atrocities, yet he and General George C. Marshall were focused chiefly on how the bomb might end the killing quickly. The advisory committee considered a demonstration against a non-city target, but rejected it: the scientific panel could not identify a demonstration likely to produce the necessary shock, and with perhaps only one bomb ready, failure could strengthen Japan’s resolve rather than end the war. The panel itself was not unanimous, but found no acceptable alternative to direct military use.

Truman later recalled that James F. Byrnes, Stimson, William D. Leahy, Marshall, and General Arnold agreed at Potsdam that the bomb should be used. He also recalled Marshall’s estimate that an invasion of the Tokyo plain and other parts of Japan would cost at least a quarter of a million American casualties. Truman said he had reached his own conclusion only after long and careful thought, and that he did not like the weapon. The narrative leaves no single, decisive instant at which he made up his mind; it emphasizes instead the momentum of the project and the pressure to secure surrender while the fighting continued. Japan’s defeat was not the same as its surrender, and each day without surrender meant more deaths.

News arrives at sea

On the morning of August 6, Truman and members of his party were on deck in the sun, listening to the ship’s band. The ship was in the Gulf Stream, south of Newfoundland; at noon its position was given as latitude 39-55 N, longitude 61-32 W, and the sea was calm. Shortly before noon, Truman and Byrnes went below to eat with the crew in the after mess. Truman had just begun lunch with six enlisted men when Captain Graham, a Map Room officer, hurried in with a map of Japan and a decoded message from the Secretary of War.

Hiroshima had been bombed four hours earlier. The initial report described the results as successful in all respects, with visible effects greater than in any test. On Graham’s map, a red pencil circled the city. Truman took Graham by the hand and exclaimed, “This is the greatest thing in history,” then directed him to show the message to Byrnes, who was seated at another table. A second report arrived minutes later, again describing the mission as a complete success and its effects as more conspicuous than those of the earlier test.

Announcement and immediate response

Truman carried the news out to cheering crew members. He was smiling broadly, though not laughing, and the dispatch suggested to him that the war might end quickly. At the officers’ ward he repeated his reaction and added, “We won the gamble.” He later said he had never been happier about an announcement. The crew’s excitement was shared by those around him; within minutes, the ship’s radio was carrying Washington bulletins and the text of the President’s statement, released by the White House shortly before.

The statement described an atomic bomb as the harnessing of the basic power of the universe and warned that the United States could destroy Japan’s above-ground productive capacity. It threatened that Japan would face a “rain of ruin from the air, the like of which has never been seen on this earth” if it did not accept the terms. The statement made no claim about the scale of destruction at Hiroshima: Washington had not yet received details. Across the country, excitement and relief spread, especially among families whose sons or husbands were serving, and many hoped the war would soon be over.

Civilian lives and the meaning of the announcement

The confident public warning coexisted with Truman’s awareness of the human cost. On August 9, responding to a correspondent who urged an unrelenting campaign against Japan, Truman wrote that he regretted the necessity of wiping out whole populations because of a nation’s leaders. He said he would not do so unless it was absolutely necessary, and described his aim as saving as many American lives as possible while acknowledging his human feeling for Japanese women and children. That night he urged Japanese civilians to leave industrial cities and save themselves.

The shift between the triumphant news aboard the ship and the later expression of regret does not resolve the moral question raised by the bombing. It shows the competing pressures that shaped Truman’s account of it: the desire to end the war and spare American lives, the expectation that the bomb could compel surrender, and the recognition that its use meant the destruction of whole populations. The first report from Hiroshima announced success before the extent of the human consequences was known.