I’ve told my kids that I don’t condone intiating violence, but if someone else starts getting physically violent first, feel free to fuck them up (provoking them will still get my kid in trouble, though).

However, if the institution itself fails to protect the kids, and my kid told me they and their friends were doing this on purpose, I’d take the day off for their suspension and take them to the arcade and a movie or something. And then I’d have a very serious talk with their principal.