That Hiroshima/Little Boy thread is something else:
As horrific and necessary the bombs were, they provided ample demonstration to ensure that they've never been used in war again.
If you view atomic bombing as "necessary", how can you go on to say that it demonstrates they should never be used again? If you've mentally justified using nuclear weapons once, how can you say there won't be a second time you justify it?
Seeing people casual talk about how necessary it was that their country committed warcrimes fills me with actual nausea.
Unlike the Germans who at the end just mostly waited for the Russians to basically steamroll them or surrendered to the allies the Japanese had fucked up moral codes that made them fight on.
The reason the US used the bomb was because Kamikaze pilots were hitting their ships. The invasion of Japan would've meant millions dead.
About 70% of all Japanese cities were already firebombed to ashes and yet they kept on fighting. Even after the first nuke the Japanese wanted to continue fighting because the general staff estimated that only 2 more atomic bombs could be made.
This point was made by McNamara in the "Fog of War". Both Atomic bombs were only responsible for a fraction of the damage to Japan. There was nothing more the US could do to force Japan to surrender.
If you want to know more about the rationale behind bombing campaigns I highly recommend you watch it. He made comparisons too, like Tokyo x% destroyed, which was like x% of New York destroyed.
In retrospect he admits they made a lot of mistakes (especially with Vietnam and the likes) and he's not trying to justify what they did, but offer an insight in what they knew then and how those decisions were made.
A lot of it came down to having a limited understanding of their enemies and a lack of communication and reliable targeting technology and sometimes relying on intelligence that was only 'partly' correct.