I think there is a contradiction in one of the things that you say. You say that counter-factuals are speculative and not useful, yet later you say the bomb sa

I think there is a contradiction in one of the things that you say. You say that counter-factuals are speculative and not useful, yet later you say the bomb saved millions of lives - that itself invokes a counter factual. i.e. The millions who would have died if the bomb hadn't been dropped (we speculate). Is it even possible to imply any causality without a counterfactual? You can obviously take things too far and start speculating on an alternative time line, but the immediate turn of events is surely a legitimate area of speculation (even for 'serious' historians) and I would say the decision to surrender in japan is one of those.