My feeling is that dropping the bomb was overall better than a land invasion, but I find the arguments against at least giving the Japanese a demonstration of the bomb - even just the footage of the Trinty test - beforehand fairly weak.
Yes, it's likely - given the Imperial Japanese military's overall disposition - that it wouldn't have been enough to cause them to surrender, in which case using the bomb on a target would be the next step. And yes, advance notice might have made those operations more difficult. But given the horror it unleashed on innocent civilians, I think the Allies had a moral obligation to try it.
Yes, it's likely - given the Imperial Japanese military's overall disposition - that it wouldn't have been enough to cause them to surrender, in which case using the bomb on a target would be the next step. And yes, advance notice might have made those operations more difficult. But given the horror it unleashed on innocent civilians, I think the Allies had a moral obligation to try it.