I’m going to disagree jmo that the bombs on Japan were necessary, and I don’t think it’s commonly agreed they were.
For one, Nagasaki was destroyed on August 9th, 1945 only 75 hours after Hiroshima was hit. Considering communications between Hiroshima and Tokyo were destroyed and they’re 450 miles separate that was extremely quick for the second bomb to come. Assuming the first bomb was still necessary, the second one coming so quick was not. To expect Japanese rulers to piece together the information of what happened (never before had something like this been seen) so fast is absurd.
Actually, on August 8th, foreign minister Togo and the emperor asked the Japanese war council to surrender. (https://www.amazon.ca/Day-One-Peter-H-Wyden/dp/1476791732)
Japan had still lost before that. March 9, an air armada dropped a carpet of incendinary bombs on Tokyo which killed around 185000 Japanese, more than both bombs combined. Japan was systematically being demolished a long time before the nukes came with many cities being in flame. The bombing of Japan previous to the atom bombs is a very interesting topic. The entire world at that time was available to surround Japan. And more importantly, Japan was an island nation short on resources. Japan needed trade to get the resources. At that point in the war, they literally only needed to blockade it until they either surrendered, or reverted to the stone age.
I don’t know why you say most people agree the bombs were necessary when even General Eisenhower, later the president told the secretary of war, “my grave misgivings, first on the basis of my belief that Japan was already defeated and that dropping the bomb was completely unnecessary, and secondly because I thought that our country should avoid shocking world opinion by the use of a weapon whose employment, I thought, no longer mandatory as a measure to save American lives. … it wasn’t necessary to hit them with that awful thing.”
Winston Churchill said, “It would be a mistake to suppose that the fate of Japan was settled by the atomic bomb. Her defeat was certain before the bomb fell, and was brought about by overwhelming maritime power. … Her shipping had been destroyed.”
America’s Chief of Staff, Admiral Leahy, said, “The use of this barbaric weapon at Hiroshima and Nagasaki was of no material assistance in our war against Japan. The Japanese were already defeated and ready to surrender because of the effective sea blockade and the successful bombing with conventional weapons.”
It’s quite clear the atom bombing was a show of muscle against Russia.