On September 2, it marked 80 years since Japan signed the Instrument of Surrender, formally ending hostilities with the Allied powers. In 1945, Emperor Shōwa decided to surrender on August 14. Why did Japan choose to accept defeat at that moment? The United States had dropped atomic bombs on Hiroshima on August 6 and Nagasaki on August 9. As a result, many claim that these bombings brought the war to an end. This past June, U.S. President Donald Trump compared American strikes on Iran to the bombings of Hiroshima and Nagasaki, stating, “That hit ended the war.” But did the atomic bombs truly end World War II?
To explore this question, we must consider two perspectives: how the Japanese government perceived the atomic bombings of Hiroshima and Nagasaki, and whether the United States intended to use them specifically to force Japan’s surrender.
What was the Japanese government’s response to the atomic bombings?
To begin, let us examine this first question. Experts have pointed out that the role of the Soviet Union’s entry into the war is often underestimated. While many believe that the atomic bombings of Hiroshima and Nagasaki brought the war to an end, another perspective holds that the Soviet declaration of war was the decisive factor. The Soviet Union declared war on Japan on August 8 – two days after the bombing of Hiroshima – and launched an invasion of Manchuria on August 9.
On June 22, 1945, Japanese leaders convened a conference in which Emperor Shōwa urged peace negotiations through Soviet mediation. This was despite the fact that, back in April, the Soviet Union had formally notified Japan of its intention to terminate the Neutrality Pact. Yet Japan continued to pin its hopes on Soviet goodwill, reasoning that the pact remained legally valid until April 1946. The Soviets, for their part, offered no clear response, leaving Japan to wait in vain for a gesture that was never likely to come.
Japan had come to recognize that it could not defeat the United States and the United Kingdom on its own. The Imperial Japanese Army’s plan for a decisive mainland battle would be rendered impossible if the Soviets joined the conflict. Thus, Japan placed its hopes on Soviet mediation, aiming to secure favorable terms for peace – most importantly, the preservation of the Emperor’s position.
Yasuaki Chijiwa, Director of the Department of International Conflict History at the National Institute for Defense Studies, notes that Japanese leaders continued to await a response from the Soviets even after the bombing of Hiroshima. It took two days to assess the devastation in Hiroshima, but once the Soviets entered the war, Japan acted swiftly. Just six hours after the Soviet invasion began, Japanese leaders convened to discuss surrender terms.
Emperor Shōwa stated, “Now that we are at war with the Soviets, it is imperative to bring the conflict to a swift conclusion.” Foreign Minister Shigenori Tōgō echoed this urgency: “We must end the war immediately.” Prime Minister Kantaro Suzuki declared, “I have decided to accept the Potsdam Declaration in order to end the war.”
Although the Army continued to insist that a mainland battle could inflict significant damage on the enemy and strengthen Japan’s negotiating position, Emperor Shōwa expressed growing distrust toward the military. He had been informed as early as June 1945 that Japan’s forces lacked the capacity to sustain such a campaign, and this realization is believed to have shifted his stance toward seeking an early peace. He resolved to accept the Potsdam Declaration, provided that the Emperor’s position would be maintained.
The Byrnes Note – a diplomatic reply issued by U.S. Secretary of State James Byrnes on August 11 – did not explicitly guarantee the continuation of the Japanese monarchy. Nevertheless, despite resistance from factions within the military, Emperor Shōwa accepted the terms of the declaration on August 14.
In summary, the two atomic bombs were not the sole or decisive factor in Japan’s decision to surrender. Japanese leaders referred to so-called “new-type bombs,” yet they struggled to comprehend the full extent of their impact in such a short time. Moreover, by that point, roughly 60 Japanese cities had already suffered catastrophic damage from large-scale incendiary bombing campaigns targeting urban populations.
A 1946 report by the United States Strategic Bombing Survey – commissioned by the U.S. military to assess the impact of aerial bombardment during World War II – concluded:
“Based on a detailed investigation of all the facts, and supported by the testimony of the surviving Japanese leaders involved, it is the Survey’s opinion that certainly prior to 31 December 1945, and in all probability prior to 1 November 1945, Japan would have surrendered even if the atomic bombs had not been dropped, even if Russia had not entered the war, and even if no invasion had been planned or contemplated.”
Did the United States intend to force Japan’s surrender through the use of atomic bombs?
This second question invites deeper scrutiny. While it is commonly accepted that the U.S. aimed to end the war by deploying atomic weapons, an alternative perspective suggests that other strategic motives may have been at play.
Professor Yasuhiro Inoue of Hiroshima City University examined the role of James Conant, then-president of Harvard University. Conant also served as chairman of the National Defense Research Committee, an organization that facilitated the militarization of academic research and ultimately contributed to the successful development of the atomic bomb. He emerged as a key architect of the scientific mobilization behind the bomb’s creation.
According to Inoue, Conant’s ultimate goal was to showcase the overwhelming power of atomic weapons to the major powers, thereby shaping the postwar world order, promoting international control of nuclear arms, and advancing the cause of global peace. For this reason, the bombs had to be detonated in densely populated urban centers without prior warning. The war, in effect, needed to continue until the bombs could be deployed.
In September 1944 – two months before the United States learned that Germany had abandoned its nuclear weapons program and eight months prior to Germany’s surrender – President Franklin Roosevelt and Prime Minister Winston Churchill secretly signed the Hyde Park Aide-Mémoire. The document included a commitment that the United States would use the atomic bomb against Japan.
In May 1945, the Interim Committee was established as a secret advisory body tasked with making recommendations on the use of atomic weapons and postwar nuclear policy. The committee rejected the precautionary measures and advised President Harry Truman to proceed with the bombings. One recommendation stated: “The most desirable target would be a vital war plant employing a large number of workers and closely surrounded by workers’ houses.” The intention was to create a plausible justification while ensuring mass civilian casualties.
Japanese researcher Tami Torii argued that President Truman, who assumed office after Roosevelt’s death in April 1945, deliberately sought to prevent Japan’s surrender until the atomic bombs could be used.
As previously noted, Japan had appealed to the Soviet Union to mediate peace negotiations. However, as early as 1943, Soviet Premier Joseph Stalin had informed the United States that the Soviet Union would enter the war against Japan following Germany’s surrender. At the Yalta Conference in February 1945, Roosevelt, Churchill, and Stalin secretly agreed to this plan, promising the Soviets territorial gains – including South Sakhalin and the Kuril Islands – despite the existence of the Soviet–Japanese Neutrality Pact. The Allies concealed from Japan the fact that the Soviets had no intention of mediating.
Torii argued that President Truman and Secretary of State James Byrnes used the Potsdam Declaration as a strategic deception. Although the Declaration was issued on July 26, it omitted the clause guaranteeing the Emperor’s position – a provision that had appeared in earlier drafts written by Secretary of War Henry Stimson. Stimson repeatedly urged Truman to inform Japan that the Allies would accept its request, but Truman deliberately avoided doing so. Moreover, the Declaration was crafted to avoid sounding like an ultimatum, subtly encouraging Japan to dismiss it. The Soviets were excluded from the Declaration, allowing Japan to continue hoping for Soviet mediation. This manipulation became evident after August 9, when Truman and Byrnes ultimately implicitly acknowledged the condition Japan had originally sought.
Ronald Takaki, former professor at the University of California, Berkeley, emphasized that the atomic bombings in Japan were part of a long-term strategy for shaping the postwar world order. Byrnes sought to use the bomb as a means of intimidating the Soviet Union. He told Truman that demonstrating its power could help ensure Soviet subordination to U.S. dominance after the war.
Final Thoughts
Japan’s stance has remained ambiguous. Public discourse largely centers on mourning Japanese victims. The education system tends to emphasize domestic suffering without holding the United States accountable for its wartime actions. Moreover, media coverage rarely questions American responsibility for the atomic bombings. Without a willingness to engage in independent study, Japan risks passively accepting the justification for their use. At the same time, Japanese society often avoids confronting its own wartime atrocities – an issue that both the education system and mainstream media frequently neglect.
Yet the world remains vulnerable to the threat of nuclear weapons and mass civilian killings. In honoring those hibakusha who have courageously spoken out against nuclear arms and shared their stories with the world, we must deepen public discussion about the broader context and hidden motives behind the bombings.
While interpretations may vary, it is time to move beyond manipulated narratives.
Source: AntiWar.com.
