Not a general strategy - "I told him that if anyone ever hits him, pushes him or punches him again he has my permission to hit back commensurately"

I wish I'd had someome tell me this when I was in grade school. I was ready to go when I was eight, nine years old, but had already learned "That's not acceptable behavior" and didn't fight back. Years and a lot of counseling later, I had some self esteem again.