Whatever labored, embarrassing arguments one can make for the nuking of Hiroshima cannot be made for the nuking of Nagasaki just three days later. From my article "Did We Really Need to Use the Atomic Bomb Against Japan?":
On August 9, 1945, just three days after we nuked Hiroshima, and before Japan’s leaders had sufficient time to process and respond to our nuclear attack on Hiroshima, we dropped an atomic bomb on the city of Nagasaki, which was home to Japan’s largest Christian population. The atomic bombing of Nagasaki was even more inexcusable than the nuking of Hiroshima. . . .
Oh nonsense. They knew exactly what damage it had done, and still resolved to fight on no matter what.
Remember. the month before when the Allies released the Potsdam Declaration, they expressly warned Japan that they would be utterly destroyed if they did not surrender. n The Japanese response? They treated it with utter contempt, the Prime Minister used the phrase "Mokusatsu", which translated to "Kill with silence" (it was not worth responding to).
Then fast forward to August. Prior to the dropping of the first bomb, the entire Privy Council was unanimous in that the war should be continued no matter what. Then on 6 August when the news of Hiroshima arrived, they took another vote. And they voted 7-1 to continue the war.
The Navy assured them that the Americans could have no more than 1 bomb, and they would still sweep them from the seas if they tried to invade. Then on 9 August came both the Soviet Invasion and the second bomb. And the warning that another bomb would be dropped in no more than a week if they did not capitulate.
And after an all night long debate, the Privy Council was ultimately deadlocked at 4-4. At that time we all know Emperor Showa threw in the towel and they decided to accept a modified surrender. Of course, then you had a coup attempt by Army diehards that still wanted to go down swinging.
If anybody thinks that Japan was about to surrender, they do not understand the nation or culture. This was a nation where death before surrender was part of their religion, and they set the pattern for suicide bombers to follow. Except instead of handfuls of fanatics, this was almost an entire nation willing to die if needed.
If the Emperor had voted the other way (after all the Council was deadlocked even after 2 bombs and another invasion), then we likely would have had to drop a 3rd, or 4th bomb. Of course by that time odds are that one of them would have been on Tokyo, and would have destroyed the Council and Emperor. At that point it literally would have been a bloodbath of epic scale.
This was a nation and culture that literally did not know the concept of "surrender".