Estimated minimum of 1.5 million Allied casualties to be incurred in a conventional invasion of Japan.
Probably 3 times that on the other side.
Therefore Atomic Bomb(s) totally justified to end War.
Q.E.D.
Might well be the case, but the burden was surely tremendous on him.
It is largely irrelevant what the bomb prevented in further losses, or foretold in terms of the Cold War - to drop the bomb itself is not something I think any of us would wish to do ourselves, simply for the knowledge of the total destruction and death it would cause upon doing so.