It was the correct decision.
This is not because I would have wanted to see Japanese civilians burn (even though, had I been alive and of age to consider it at the time, I am pretty sure I would have wholeheartedly and enthusiastically approved of its use, given the climate of the day)
If they had it, they would have unhesitatingly used it against us, as would have the Nazis. Of that, I have no doubt.
Did the Japanese Atomic Bomb Prompt Ours?
We now mark the 79th anniversary of dropping atomic bombs on Japan to end WW II. The decision not only considered horrendous casualties in the millions but had to assess Japan’s nuclear program. As WW II began, the U.S. knew Japanese intellectuals included accomplished physicists such as Yoshio Nishina. They knew he was a staunch Imperial nationalist and capable leader; so capable two students later won Nobel prizes. They knew he had built Japan’s first cyclotron in 1940.
Yet much was unknown throughout the war because America found Japan impenetrable except for cryptographic intelligence and photo reconnaissance. The allies had no agents in the Home Islands and most communication was by land line. Americans had to rely upon their primary principle for minimizing the uncertainties of intelligence analysis by deciding enemies will focus their command economies on realization of the most devastating weapon capabilities.
The next American insight into Japan’s progress came in May 1945 as Germany surrendered. Admiral Doenitz ordered all submarines to proceed to allied ports. In Portsmouth, the Navy discovered U-234’s cargo contained 560 kilos of uranium oxide destined for Japan and for refinement into fissionable material.
After the war historical research confirmed how close the Japanese came. They discovered Nishina used his substantial budget to conduct work at the large industrial complex at Hungnam Korea. One day after the Nagasaki bomb, Japan exploded an experimental nuclear device off that coast. Stalin’s forces captured Hungnam and Japanese equipment and scientists vanished inside the Soviet Union.
Partial bibliography:
Japan’s Secret War: Japan’s Race Against Time to Build Its Own Atomic Bomb, Robert K Wilcox
The Making of the Atomic Bomb Richard Rhodes
Yoshio Nishina
https://en.wikipedia.org/wiki/Yoshio_Nishina