World War II in the Pacific came to an end in August 1945, when Japan surrendered unconditionally to the Unites States and its allies. According to the standard story in the U.S., it was the American atomic bombings of Hiroshima and Nagasaki that brought Japan to surrender, thus preventing many more months of vicious warfare. However, this story is hotly debated among historians, with many asserting that Japan was going to surrender anyway and that the bombings were therefore an unnecessary spectacle of death and destruction.

Japanese Strategy

By summer of 1945, the war was already winding down, with Japan on the defensive and most of its major cities already severely damaged by conventional bombing. The U.S. was demanding unconditional surrender, but the Japanese government wanted to avoid the prospect of its country being completely restructured and its leadership put on trial for war crimes as had already begun happening to the recently-defeated Nazi Germany. Historian Ward Wilson explains that Japan’s leadership was hoping to find a way to surrender on its own terms, either by asking the then-neutral Soviet Union to mediate a resolution, or by defending Japan’s main islands so fiercely from the coming American invasion that the U.S. would be forced to compromise.

Change of Plans

Japan’s Supreme Council was considering unconditional surrender around the same time the atomic bombs were dropped, but many historians argue that the bombs weren’t what forced their hand. The argument that the atomic bombings were unnecessary to end the war was first made well-known by historian Gar Alperovitz in 1965, and the issue has been a major topic of discussion ever since. Ward Wilson asserts that the turning point was the Soviet Union’s sudden declaration of war and preparations to invade Japan’s north. With the U.S. and the Soviet Union both invading from different directions, there was no longer hope for any compromise.

The Evidence

Wilson points out that Japan’s Supreme Council actually declined to meet after the first nuclear bombing in Hiroshima, finally gathering to discuss unconditional surrender three days later, just after Russia declared war – and just before the second atomic bomb was dropped on Nagasaki. He also asserts that Hiroshima and Nagasaki were actually relatively minor losses for Japan’s hardened military leadership, since Tokyo and most of the country’s other major cities had already been largely bombed to the ground using conventional weapons.

Did the U.S. Know?

If the U.S. leadership didn’t know at the time that Japan was already considering surrender, perhaps even President Harry Truman believed the atomic bombings were necessary to end the war. However that wasn’t the case: the U.S. had already intercepted communications from Japan showing that the emperor had asked the Russians to mediate a surrender, and almost every top U.S. military leader from the time later came forward saying that Japan was already defeated before the bombs were dropped. The remaining debate between historians is less about whether Japan was already going to surrender, and more about why the U.S. used the atomic bombs at all. On the one hand, some argue that President Truman saw the bomb as just one more legitimate weapon to continue fighting with until the end, but others insist that the actual purpose was to intimidate the Russians and secure the U.S. as the winner at the beginning of the Cold War.