I can understand the justification given for the use in World War II–that is, the degree to which it was likely that the war would have been dragged onto the Japanese mainland and that non-combatants such as prisoners of war were to have been sacrificed by their captors. I don’t know that the ramifications of the totality of damage from a nuclear weapon were fully appreciated, though. I am not going to say the moral reasoning at the time, knowing what the situation was at the time, was defective. I suppose that says that I can imagine a possibly-not automatically-immoral use situation?
No, taking into account what modern nuclear weapons have become and what we appreciate now about the extent and duration of the damage they inflict, I don’t see a moral use for them going forward. The question now, though, is what to do with the ones we have? Some of the total extent of the damage of a nuclear bomb is in the construction of it, and that is done. It can be cheaper to enrich new material than it is to downgrade and re-purpose weapons-grade materials. Of course, if they aren’t de-activated, then there is a chance someone will choose to use them. It is a crazy world, these days.