Well, when it comes to real-world ethical questions, there’s frequently not only a third choice (“do nothing”) but a fourth and a fifth and a sixth, being various other things that could be done. (E.g. steer your car the other way, not towards the oncoming car but towards the tree. Perhaps that will save the child at no risk to the driver of the other car, but a greater risk to you and your passenger.)
And, of course, the outcome of the choices we don’t take can never be absolutely known. And when we are contemplating them as possibilities or options, we’ll frequently have very poor information about what the outcomes of each would be. (Is the driver of the other car wearing their seatbelt? Is there an unrestrained infant in the back seat? These are not things I can necessarily see and/or take account of in the split-second that I have to make my decision.)
This will be true of many real-world ethical dilemmas that have been faced by people other than ourselves, won’t it?
So I’m not sure that the primary value of discussions like this is to enable us, in a particular historical event, to judge a particular person to have acted morally or immorally. Rather, it’s to allow us to discuss the principles that we believe ought to govern a dilemma of this kind. Once we have identified the principles actually applying them might be very difficult because of poor information, limited time or external constraints, but that’s not really the point. We can’t even attempt to apply sound principles to such a dilemma if we haven’t worked out what principles would be sound.
The very fact that you’re fighting a war at all means that you are willing to accept that, in some circumstances, some killing is justified. So I don’t think you can say that avoiding killing people is an absolute and overriding moral principle which eclipses all others.
On the other hand, I think most people’s moral instinct would be to say that killing is, by default, not justified. If you seek to justify a particular instance of killing you have to point to particular circumstances that justify it. So then you have to ask yourself awkward questions about the circumstances in which killing is justified.
Some insight can be gained here, maybe, by asking ourselves why, in post #1, did Velocity offer the bombing of Hiroshima as an instance of an atrocity? I agree, characterising it as an atrocity may have poisoned the well, but we can still ask ourselves why anybody might be tempted to call it an atrocity And a couple of features immediately suggest themselves - this was an indiscriminate weapon (a “weapon of mass destruction”, as Dubya use to say); it was targeted at a largely noncombatant population; its deployment was allegedly motivated by a desire to enhance American prestige and influence, and not merely by a desire to save lives; to the extent that its deployment was motivated by a desire to save lives, it allegedly prioritised American (combatant) lives over Japanese (noncombatant) lives. And so forth.
The question worth discussing is not whether these claims are true in relation to the Hiroshima bombing, but rather whether they point to the kind of considerations that we think would or might be morally relevant. Do we agree, in other words, that it’s harder (or impossible) to justify attacks on noncombatants? Do we agree that each protagonist can (or even should) prioritise the lives of its own over the lives of the other? If we agree that some lives enjoy a greater moral “protection” than others, does it follow that the use of weapons which don’t distinguish must be unjustified? Is the sheer scale of the loss of life a morally relevant consideration? Is it acceptable to kill people in order to enhance your power or status? Interrogating questions like that - ideally, without identifying with either side in the particular historical example chosen to illuminate the questions - is the kind of exercise that enables us to grope our way towards identifying the principles we need.