The Biggest Decision: Why We Had To Drop The Atomic Bomb


Marshall reported that the chiefs, supported by the Pacific commanders Gen. Douglas MacArthur and Adm. Chester W. Nimitz, agreed that an invasion of Kyushu “appears to be the least costly worthwhile operation following Okinawa.” Lodgment in Kyushu, he said, was necessary to make blockade and bombardment more effective and to serve as a staging area for the invasion of Japan’s main island of Honshu. The chiefs recommended a target date of November 1 for the first phase, code-named Olympic, because delay would give the Japanese more time to prepare and because bad weather might postpone the invasion “and hence the end of the war” for up to six months. Marshall said that in his opinion, Olympic was “the only course to pursue.” The chiefs also proposed that Operation Cornet be launched against Honshu on March 1, 1946.

Leahy’s memorandum calling the meeting had asked for casualty projections which that invasion might be expected to produce. Marshall stated that campaigns in the Pacific had been so diverse “it is considered wrong” to make total estimates. All he would say was that casualties during the first thirty days on Kyushu should not exceed those sustained in taking Luzon in the Philippines—31,000 men killed, wounded, or missing in action. “It is a grim fact,” Marshall said, “that there is not an easy, bloodless way to victory in war.” Leahy estimated a higher casualty rate similar to Okinawa, and King guessed somewhere in between.

King and Eaker, speaking for the Navy and the Army Air Forces respectively, endorsed Marshall’s proposals. King said that he had become convinced that Kyushu was “the key to the success of any siege operations.” He recommended that “we should do Kyushu now” and begin preparations for invading Honshu. Eaker “agreed completely” with Marshall. He said he had just received a message from Arnold also expressing “complete agreement.” Air Force plans called for the use of forty groups of heavy bombers, which “could not be deployed without the use of airfields on Kyushu.” Stimson and Forrestal concurred.

Truman summed up. He considered “the Kyushu plan all right from the military standpoint” and directed the chiefs to “go ahead with it.” He said he “had hoped that there was a possibility of preventing an Okinawa from one end of Japan to the other,” but “he was clear on the situation now” and was “quite sure” the chiefs should proceed with the plan. Just before the meeting adjourned, McCloy raised the possibility of avoiding an invasion by warning the Japanese that the United States would employ atomic weapons if there were no surrender. The ensuing discussion was inconclusive because the first test was a month away and no one could be sure the weapons would work.

In his memoirs Truman claimed that using atomic bombs prevented an invasion that would have cost 500,000 American lives. Other officials mentioned the same or even higher figures. Critics have assailed such statements as gross exaggerations designed to forestall scrutiny of Truman’s real motives. They have given wide publicity to a report prepared by the Joint War Plans Committee (JWPC) for the chiefs’ meeting with Truman. The committee estimated that the invasion of Kyushu, followed by that of Honshu, as the chiefs proposed, would cost approximately 40,000 dead, 150,000 wounded, and 3,500 missing in action for a total of 193,500 casualties.

That those responsible for a decision should exaggerate the consequences of alternatives is commonplace. Some who cite the JWPC report profess to see more sinister motives, insisting that such “low” casualty projections call into question the very idea that atomic bombs were used to avoid heavy losses. By discrediting that justification as a cover-up, they seek to bolster their contention that the bombs really were used to permit the employment of “atomic diplomacy” against the Soviet Union.

The notion that 193,500 anticipated casualties were too insignificant to have caused Truman to resort to atomic bombs might seem bizarre to anyone other than an academic, but let it pass. Those who have cited the JWPC report in countless op-ed pieces in newspapers and in magazine articles have created a myth by omitting key considerations: First, the report itself is studded with qualifications that casualties “are not subject to accurate estimate” and that the projection “is admittedly only an educated guess.” Second, the figures never were conveyed to Truman. They were excised at high military echelons, which is why Marshall cited only estimates for the first thirty days on Kyushu. And indeed, subsequent Japanese troop buildups on Kyushu rendered the JWPC estimates totally irrelevent by the time the first atomic bomb was dropped.

Another myth that has attained wide attention is that at least several of Truman’s top military advisers later informed him that using atomic bombs against Japan would be militarily unnecessary or immoral, or both. There is no persuasive evidence that any of them did so. None of the Joint Chiefs ever made such a claim, although one inventive author has tried to make it appear that Leahy did by braiding together several unrelated passages from the admiral’s memoirs. Actually, two days after Hiroshima, Truman told aides that Leahy had “said up to the last that it wouldn’t go off.”