How about books to keep you from having to engage in Combat?
I've read all of these and all were worth the price of the book and the time to read them. I consider the first two as "must reads" for ANYONE.
The Gift of Fear - Gavin De Becker
Verbal judo - George J. Thompson
Safe in the City - Marc MacYoung
Violence, Blunders, and Fractured Jaws - Marc MacYoung
Mindhunter - John Douglas
Journey into Darkness - John Douglas
True Tails of American Violence - Chris Pfouts
What Cops Know - Connie Fletcher