Hmmm......
Wake up! there is no such thing as innocent civilians
They were part of the nation that brought the US's wrath upon themselves.
The elegant and puerile simplicity of it is breathtaking.
"... as immoral as if you lined them up and shot them one by one...
Put that statement before a first grader, and he would not take long to point out that "one by one" makes is possible to make the easy moral choice.
When your definition of a "moral choice" is the operating imperative, the only alternatives are the difficult moral choice, or to do nothing.
If you can't see the obvious difference...
Have a nice day.
You seem to be of the opinion that soldiers deserve what they get, but innocent civilians should be spared.
Most soldiers, worldwide and throughout history, were "innocent civilians" until their governments ordered/forced them to become soldiers, they really had no choice in the matter of becoming a soldier.
How is it moral to kill these uniformed innocent civilians, but its not morally OK to kill someone merely because their government hasnt yet ordered them to wear a uniform?
It would be great if all killing and wars were done away with, but history shows us the best way to kill the fewest people in a war is to end the war the quickest way possible, which the A-bombs over Japan did.
You quote (truthfully I hope) a few subordinates who thought Japan was ready to surrender at any minute, and they didnt think we should have dropped the A-bombs on Japan. What if they were wrong? What if many more hundreds of thousands on both sides were killed before the war was concluded? Would you just say tough luck?
The man with the most information and overall responsibility, President Harry Truman, decided that the A-bomb was the correct weapon. Unlike the scenarios you present, Japan did not immediately surrender after the first A-bomb. Even after the second A-bomb the Japanese military were ready to keep fighting. Only when the Emperor stepped in and said in effect no more did Japan finally quit fighting.
One can play pointless what if and should have games forever, I believe we made the tough yet correct decision to drop the A-bombs on an aggressive expansionist country that needed to be stopped.