My contention, and I'll admit it's wholly academic, is that another way could have been found.
Actually no other ways could be found, hence we dropped two atomic weapons. Some of the Japanese military leadership tried to find ways to negotiate but the Emperor wouldn't have anything of it. It wasn't until after Nagasaki that the Emperor realized he was completely crushed. Then the Prime Minister was able to take over and negotiate.
Also, try telling the troops on the ground that you have access to this weapon that could get them to capitulate without any of our boys having to land on Japanese soil, but we aren't going to use it because, well it would just do too much damage.
The only thing I can say is you would have mutiny on your hands.
The parallels to today are striking. I heard it recommended recently that we should fall back to our 'MAD' mutually assured destruction that kept USSR in check for 40 years.
Tell the Muzzies that they got the World Trade Center, if we get hit again we take out Tehran. If they continue, we hit Damascus. If they continue, we hit Mecca, during the Haj, etc.
At some point they WILL learn that we are serious and that we are not to be #^$*ed with. Everything else is pussyfooting around the problem.
Don't bring up the WTC, SFC. I walked out of 1 WTC on September 11. You may think you're making a valid point, but not to one who was actually there and survived.
While nuking Mecca or Tehran may be satisfying, it does nothing to mitigate the cause of Islamofascism, which is a mindset incapable of dealing with the modern world. So,what is your ultimate goal here; destroying people because they happen to Muslim or destroying a culture which produced a poisonous ideology? I'd opt for #2, and while that does involve military action, it does not require that we slaughter a billion people.