Overall, I think it is important to have these issues thoroughly resolved in your own mind so that you are mentally prepared. Nothing is as calming or as definitive as being the one person in the room who is aware, prepared, and ready to act in an instant. I would offer that many times it is palpable (not always) to others.
And thus is the purpose of Budo. I think this is the bottomline of all we can really do in the end. The outcome, you cannot predict, but it really doesn't matter as long as you did what you did without emotion, excess, and you do it for the right reasons.
I think it is dangerous going into any situations with a so-called "ethical Aiki way" that dictates a right and wrong way to do things and states that you failed if you did not peacefully resolve things. I think in many cases this process is out of our hands and we must allow ourselves to be free of such notions.
We do what we can do to prepare to have a clear mind and be prepared to do what we can do...outside of that we have to be willing to go the distance if need be.