There is no question. I will attack him.
If I die in the process, I will do my best to render him unable to continue his assault first.
Naturally, I will try my best to be smart about it, and may feign compliance at first in order to catch him in a moment of distraction... but he isn't laying a hand on my wife while I breathe.
IMHO, a man who would do any less is no man at all.... or else he cares very little about his wife.