July 25, 1945 Atomic-Bomb Operations Directive

The July 25, 1945 Atomic-Bomb Operations Directive translated the decision to use the atomic bomb against Japan into an operational order. Issued by General Thomas T. Handy to General Carl A. Spaatz of the Twentieth Air Force, it also provided that additional bombs would be sent to the designated targets as soon as they were ready. That provision proved decisive: a second bomb was dispatched under the existing directive, without a new high-level meeting or a further decision by Harry S. Truman.

From secrecy to presidential decision

The directive followed a long period in which the bomb’s development was concealed even from members of the Senate committee investigating wartime procurement. Staff investigators had encountered unexplained expenditures associated with the Manhattan Project. When Truman telephoned Secretary of War Henry L. Stimson on June 17, 1943, Stimson told him that only a handful of people knew about a highly important secret development. Truman accepted Stimson’s assurance that it served a specific and unique purpose. By July, he had learned the project’s essential nature, though the secrecy surrounding it remained substantial.

In the spring of 1945, Stimson brought Truman a memorandum warning that within months the United States would probably possess a weapon capable of destroying a city. The United States was then the only country able to produce it, but Stimson expected that monopoly would not last and identified the Soviet Union as a possible future atomic power. The bomb therefore presented a decision about ending the war as well as a question of what the new weapon meant for the postwar world.

The urgency of that decision was shaped by the human cost of continuing the war. On June 18, Truman considered whether to invade Japan or instead bomb and blockade it, calling the choice his hardest decision to date; the bomb was not mentioned at the invasion-planning meeting that afternoon. In July, Truman later recalled that General George C. Marshall estimated an invasion of the Tokyo plain and other parts of Japan would cost at least a quarter of a million American casualties. He said he reached his conclusion only after long and careful thought and did not like the weapon.

The choice of use

The directive emerged from deliberations in which alternatives to attacking a city had been considered. A technical demonstration intended to warn Japan without causing mass casualties was rejected by the committee and its scientific panel: with probably only one bomb ready, and uncertainty about whether it would work, a failed demonstration could strengthen Japanese resistance rather than compel surrender. The panel concluded that it could identify no demonstration likely to end the war and no acceptable alternative to direct military use. Earlier, General Marshall had considered striking a military installation first and warning people to leave manufacturing centers if further attacks became necessary; by this stage, he had changed his mind.

The moral stakes remained visible even among those who favored using the weapon. Stimson worried that the United States should not outdo Hitler in atrocities, while also raising the disturbing concern that conventional raids might leave too little of a target intact to demonstrate the atomic bomb’s power. Truman reportedly laughed at that juxtaposition, then said he understood. The directive’s operational language belonged to this larger argument: military advisers sought a shock that would bring surrender and end the killing, while the contemplated method risked destroying whole populations.

On July 24 at Number 2 Kaiserstrasse, Truman met with Winston Churchill and the combined American and British Chiefs of Staff. The book identifies this meeting as the point after which, barring unforeseen developments, use of the bomb was settled. Later that day at Cecilienhof Palace, Truman told Joseph Stalin that the United States had a weapon of unusual destructive force; Stalin replied that he hoped it would be put to good use against Japan. The following day, Handy transmitted the operations directive to Spaatz.

What the directive authorized

The directive included an instruction for what would happen after the first bomb: “Additional bombs will be delivered on the above targets as soon as made ready by the project staff….” The sentence made readiness, rather than a new presidential conference, the stated condition for delivering further weapons. It established an operational mechanism within the military order, although the evidence does not reproduce the full directive or identify all of its target details.

That distinction became consequential in August. After the first bomb was used, there was no new high-level meeting about the second, and Truman made no additional decision. No separate order was issued beyond the July 25 directive. When the plutonium bomb nicknamed Fat Man was ready, it was dispatched from Tinian two days ahead of schedule because of weather conditions. The account therefore presents the directive not merely as a record of the initial authorization but as the standing instruction under which the second bomb was delivered.

Execution and limits

The second attack sharpened the question of what authority the standing order left in practice. On August 9, the same day newspapers reported that Soviet forces had entered Manchuria and that the bomb had been dropped on Nagasaki, Truman wrote that he regretted the necessity of wiping out whole populations because of the decisions of a nation’s leaders. He said he would not do so unless absolutely necessary, hoped Japan would surrender after Soviet entry into the war, and described saving American lives as his object while acknowledging his human concern for Japanese women and children.

That evening, Truman urged Japanese civilians to leave industrial cities and save themselves. His statements do not amount to a revision of the July 25 directive: the evidence says no additional order followed it. Instead, they reveal the tension between the directive’s ready-to-deliver provision and Truman’s subsequent insistence that destroying populations should not be undertaken unless necessary. The order’s historical significance lies in that combination of presidential authorization, military execution, and the absence of a fresh decision before the second bomb was sent.