I agree...walk away before it escalates...but I told my daughter if someone puts hands on you, you better fight back.
I remember back in middle school I wasn't really much of a fighter back then, and I did the whole walking away thing and got jumped by these girls...So sometimes even walking away doesn't work...cause some bullies will end up following you and if you tell on them, it can get worse.
But I think that's a good idea for putting your child is a self-defense program, it also teaches them self-discipline.