By the time the bomb was ready for use, Japan was ready to surrender. As General Dwight Eisenhower said, Japan was at that very moment seeking some way to surrender with minimum loss of face, and ‘it wasn’t necessary to hit them with that awful thing.’ So if Japan was ready to surrender, why were atomic bombs dropped on Hiroshima and Nagasaki?

A significant factor was the US’s desire to establish its dominance in the region after the war. US planners believed that this required US occupation of Japan, enabling it to establish a permanent military presence and dominate the Pacific region without fear of Japanese resurgence. But Japanese resurgence was no longer the US’s key strategic concern in the postwar world; its main concern was the Soviet Union.

The Soviet Union was the US’s wartime ally against Germany. However, their political and economic systems were incompatible; the US would not accept that any part of the world economy should be closed to it, and those seeking an alternative to the market economic model of the US tended to look to the Soviet Union. This looming antagonism was heightened by the increased power and prestige of the Soviet Union, following its role in breaking the back of Germany’s military machine. The US consequently wished to prevent a Soviet advance in Asia and subsequent Soviet influence on Japan.

One is forced to conclude that the US wanted to demonstrate its unique military power – its possession of the atomic bomb – in order to gain political and diplomatic advantage over the Soviet Union in the postwar settlement in both Asia and Europe. As eminent US historian Gar Alperovitz observes:

“Modern research findings clearly demonstrate that from April 1945 on, top American officials calculated that using the atomic bomb would enormously bolster US diplomacy vis-a-vis the Soviet Union in negotiations over both postwar Europe and Asia. The atomic bomb was not, in fact, initially brought to Truman’s attention because of its relationship to the war against Japan, but because of its likely impact on diplomacy.”

Many leading US politicians, diplomats and military figures thought it unnecessary to bomb Japan, but the group around President Truman pressed strongly for it. Secretary of War Henry Stimson, even described the atom bomb as the ‘master card’ in US diplomacy towards the Soviet Union.

By early 1945 it was clear that the Japanese government was seeking a negotiated surrender. Its only condition was that the Emperor, Hirohito, would be maintained without loss of face and exempted from war crimes charges that could have led to his execution, as they did with many leaders of Nazi Germany.

There was general agreement amongst the Western leaders that this was acceptable but the US leadership did not inform the Japanese. If they had, the Japanese would have surrendered, thereby removing the excuse the US needed to use the bomb.

The bomb was used to demonstrate the awesome power of the US in a world where it was the sole possessor of this terrible weapon.