“Three is the perfect number,” the saying goes. But when it comes to the atomic bomb, two were already too many, and the third… well, the third is a story that few people know. It is the story of a weapon that never exploded, of a threat that hung over Japan like a sword of Damocles, and of a “demonic” piece of plutonium that seemed to have a will of its own.
Get ready for a journey into the dark side of the end of the Second World War, through the US plans to continue to strike Japan until the end.
The historical context: a Japan on the brink of the abyss
In August 1945, the world had just been shaken by the devastating explosions of the atomic bomb dropped on Hiroshima and the one dropped on Nagasaki. Japan, stubbornly proud and determined, faced a crucial decision: surrender or continue fighting despite catastrophic losses.
The Japanese government was deeply divided on this issue. On the one hand, there were the civilian ministers who feared a Soviet invasion and were inclined to surrender, provided that the emperor could maintain his role. On the other hand, the military pushed to continue the war until the last drop of blood. The admiral Soemu Toyoda, Chief of Staff of the Navy, was among the most ardent supporters of all-out war, because, he argued, the United States would only have a few atomic bombs available. Maybe only the two just launched.
Ironically, Toyoda was not far from the truth. The details, though, would have made all the difference in the world.
The preparation of the third atomic bomb
After Nagasaki, the United States had enough plutonium for only one more core, which still required days of preparation. The unfavorable weather forecast for Japan was clear: a third atomic bomb would not be available until August 17-19 (reminder: Hiroshima was hit on August 6, Nagasaki on the 9th).
Meanwhile, American President Truman, surprised by the speed with which the first two had been dropped, had ordered that no other atomic bombs be used without his explicit authorization. To increase pressure on the Japanese government, however, Truman publicly declared that the United States was prepared to continue the use of atomic weapons until Japan surrendered.
The race against time
While the Japanese cabinet debated, locked in a stalemate, the third plutonium core was completed and transported to California. From there, if necessary, he would be sent to the B-29 base on Tinian, the island not far from the Philippines, to be inserted into another weapon.
The 14 August, with the question of the emperor's future status still unresolved, Truman dissolved his reservations. He authorized new fire raids on Japan to increase the pressure, and the US military planned another nuclear attack for August 19. Or the next day of good weather, if Japan continued to refuse to surrender.
The mystery of the lens
Which city would be the target of this third atomic bomb? Speculations abound, but there is no official information on this point. Tokyo this is unlikely, given that the United States was negotiating with the Japanese government. Yokohama o Sapporo, relatively little damaged by the incendiary bombings, were instead concrete possibilities.
In light of the facts, however, considering previous events, it is likely that the primary objective would have been kokura, originally designated for the second atomic bomb but saved at the last moment due to cloud cover. Niigata, also on the original list of atomic targets, may have been chosen as a secondary target.
The surrender and fate of the third atomic bomb
In the end, fortunately the third atomic bomb proved unnecessary. On the night of August 14, 1945 the Japanese cabinet, pushed by the emperor, finally decided to accept unconditional surrender. The message was sent to the Allies the next day, ending the war.
The plutonium core destined for the third atomic bomb, however, had a troubled history of its own. Sent to Los Alamos for experiments, he was the protagonist of two fatal accidents that earned him the nickname "demonic nucleus". The August 21th, 1945, the physical Harry Daghlian died from radiation exposure during an experiment. A few months later, in May 1946, a similar accident cost the life of physicist Louis Slotin.
The legacy of the bomb that was never dropped
The “demonic core” was intended for Operation Crossroads in July 1946, a series of nuclear tests at sea. However, after the first two tests, the third was cancelled. The core was finally melted down in August 1946 and its plutonium incorporated into new atomic nuclei.
The story of the third atomic bomb is a little-known but profoundly significant chapter of the Second World War. It represents not only the end of a devastating conflict, but also the beginning of the nuclear age, with all its promise and dangers.
The thread that separated the world from a further nuclear catastrophe was very short. The decisions made in those frenetic days shaped not only the end of the war, but also the course of subsequent history. That bomb, never dropped, is yet another lesson that even decades later we cannot afford to forget.
