Atomic bombing of Nagasaki

The Atomic bombing of Nagasaki on August 9, 1945, brought a second atomic weapon to bear on Japan while its leaders were still divided over surrender. Its immediate significance lay not only in the destruction and loss of life, but in the circumstances of its use: no new high-level decision had been made for this second bomb, the Soviet Union entered the war against Japan that day, and the news helped bring Japan’s deadlocked leadership back to the question of surrender.

Background and the Decision to Use the Bomb

By the summer of 1945, Japan’s cities had already endured devastating conventional air raids. A March firebombing of Tokyo had killed more than 100,000 people, and attacks on other industrial and coastal cities continued. The prospect of further destruction was therefore not abstract. Yet decision-makers were also confronting the prospect that Japan, though defeated in military terms, might not surrender, prolonging the fighting and its mounting human cost.

The committee advising the President considered whether to demonstrate the new weapon without striking a city. That option was rejected: the scientific panel could identify no demonstration likely to produce the needed shock, and officials worried that a failure would strengthen Japan’s resolve. Earlier, General Marshall had considered a military target followed, if necessary, by attacks on manufacturing centers with advance warnings. By the time of the final deliberations, the discussion had centered on how to use the bomb to bring the war to an end quickly. Stimson emphasized that the committee advised; responsibility for the recommendation rested with him.

At Potsdam, Truman later recalled a consensus among Byrnes, Stimson, Leahy, Marshall, and General Arnold that the bomb should be used. Marshall had stressed the likely cost of an invasion: he estimated at least a quarter of a million American casualties. Truman said he reached his conclusion after long and careful thought and did not like the weapon. The book presents this decision against a grim contrast: Japan’s defeat was not the same as its surrender, and the continued fighting meant further deaths while American casualties in the Pacific had risen sharply in the months after Truman took office.

The Bombing and the Standing Order

On August 9, newspapers reported two immense developments: a million Soviet troops had crossed into Manchuria, and a second atomic bomb had been dropped on Nagasaki, a major Japanese seaport. The weapon, a plutonium bomb nicknamed Fat Man, had been delivered from Tinian. It was used two days ahead of schedule because of weather conditions.

Unlike the decision to use the first bomb, the second attack was not preceded by a new high-level meeting or an additional presidential decision. The military directive for the first bomb, sent on July 25 by General Thomas T. Handy to General Carl A. Spaatz of the Twentieth Air Force, already provided for further attacks: “Additional bombs will be delivered on the above targets as soon as made ready by the project staff….” Once the second weapon was ready, it was delivered under that instruction. The distinction is consequential: Nagasaki followed an established operational order, not a newly recorded presidential deliberation about this particular attack.

Later estimates put the death toll at Nagasaki at 70,000. The damage would have been worse had the bombardier not been two miles off target. News coverage framed the attack as evidence of the weapon’s devastating effect, and many observers on Capitol Hill expected the war to end soon. But the reports of destruction did not settle the immediate question of what Japan would do.

Truman’s Response and the Human Cost

On August 9, Senator Richard B. Russell Jr. urged Truman not to ease the assault. In his view, the United States should continue until Japan accepted unconditional surrender, using conventional incendiary bombs if more atomic weapons were not yet available. Russell invoked Pearl Harbor and the conduct of the Japanese military to argue against leniency.

Truman answered that he could not accept the idea that the United States should act as brutally as an enemy it condemned. He regretted the necessity of destroying whole populations because of their leaders’ stubbornness, and said he would not do so again unless absolutely necessary. He believed that Soviet entry into the war would soon cause Japan to give way, while insisting that his aim was to save American lives and that he had “a human feeling for the women and children of Japan.” His response registered both the military purpose he claimed for the bomb and the civilian suffering that purpose entailed.

That night, in a radio address about Potsdam, Truman told the American public that the bomb had not been produced or used lightly. He presented its use as an effort to shorten the war and save American lives, and said that only Japanese surrender would stop the attacks. He also urged Japanese civilians to leave industrial cities immediately. Reflecting on the new weapon, he described the responsibility it had brought as “an awful responsibility.” The address framed atomic power as an instrument of war, but also as a grave burden on those who commanded it.

Japan’s Deliberation and the Aftermath

The bombing coincided with a decisive crisis inside Japan’s leadership. On the morning of the attack, the Supreme Council for the Direction of the War was meeting in Prime Minister Suzuki’s bomb shelter outside the Imperial Palace in Tokyo. The council was deadlocked. Three senior military commanders opposed surrender, while War Minister Korechika Anami called for one last great battle on Japanese soil and appealed to the national honor of the living and the dead.

When news of Nagasaki reached the meeting, the council adjourned and reconvened that night with Hirohito. Less than twenty-four hours after the bombing, the Emperor decided that Japan must “bear the unbearable” and surrender. The Japanese government accepted the Potsdam Declaration on the understanding that the Emperor would remain sovereign. The declaration had promised humane treatment and said the Japanese people would not be enslaved as a race or destroyed as a nation; it called for the removal of Japan’s capacity to wage war and a freely elected, peaceably inclined government. Its final paragraph demanded the unconditional surrender of the armed forces, while leaving the Emperor’s future unaddressed and warning of “prompt and utter destruction.”

The sequence does not reduce Japan’s surrender to a single cause: the Soviet Union’s entry into the war, the atomic attack, and the internal deadlock all formed part of the crisis. Nagasaki marked the second use of the weapon and sharpened the immediate pressure for a decision, while exposing the distance between the promise of a decisive military shock and its human cost.