That's a matter of context, and raises the question of whether they're in a civil society or a war (or both at once). In principle in a civil society nobody should be punching anybody in the face and mitigating circumstances like the other person being a nazi are only details. But see Sartre's feelings about living alongside nazis in occupied France: the were very polite and pleasant, and the whole situation was tense and awkward because you're unsure of your duty in that situation - is it war or not?
Is this a quote from Sartre, or just an interpretation? I looked for it and couldn’t find it, beyond maybe representing his “Paris under the occupation”
I highly recommend using it via https://aistudio.google.com/. Gemini app has some additional bells and whistles, but for some reason quality isn't always on par with aistudio. Also Gemini app seems to have more filters -- it seems more shy answering controversial topics. Just some general impressions.