I believe in the lesser evil principle, but I have limits. Everyone must decide for himself where to draw the line. Speaking for myself, there's a point beyond which it becomes too personally compromising.
You can't back me into a corner, then say, "I double dare you to accept the consequences if you refuse to choose between two alternatives I've given you!"
I won't allow myself to be manipulated and maneuvered by circumstances beyond a certain point. It becomes almost diabolical.
At that juncture I will walk away from the table and let the chips fall where they may. I'm not ultimately responsible for what happens. I didn't make the world. I didn't create this situation.
If you dictate unacceptable choices to me, I will bow out. I can't control the world, but I can control my own actions. You can't make me choose a certain way by putting a gun to my head. You can't prescribe how I must choose. If the options become too awful, I withdraw from the game. I won't play by your rules. I refuse to collaborate. If you win by default, so be it. I leave it to God sort out the consequences.
There can be situations in which a human being confronts us with a moral dilemma. We either do one of two things or else!
That's still different than God confronting us with a moral dilemma, because the "or else" option is still available.
Suppose I'm a German Jew. The Nazis round up my parents and me and put us on a train. When we arrive at the camp, Himmler is touring the camp.
He gives me a choice: If I shoot one of my parents, he will allow the other to go free. (And he has the authority to release my remaining parent). If I refuse, he will shoot them both.
In that situation I'd let him shoot them both, and leave the matter in God's hands. The dilemma is a way for him to make me cross over into his moral universe.
But I can't go there. I must stay on my side of the moral boundary, regardless of the threat. I won't be party to his diabolical game.
Conversely, suppose that's the camp where Mengele performed human experiments. If my parents were picked, I might wrest a gun from the guard and shoot them myself to spare them that fate. That's a horrible choice, but unlike the first, I don't think it's morally compromising.