This is purely anecdotal and based on what I saw and did, but in an environment like that, it seems to me that escalation is only a problem if you don't escalate quickly enough. If I ended up in a fight (and I probably could have resolved a lot of conflicts without fighting, but I had that perfect combination of arrogance and insecurity that plagues the teenage mind), the problems continued only if I lost easily. Some of the best advice my mother gave me was "You can at least get a sandwich if they got a meal." (Other hits from mom: "The secret ingredient is always more butter." A stout lady, most of her advice was either directly about food or used a food analogy.) If I won, or if I managed to hit hard enough in the process of losing, I'd get no more trouble, except in one pathological case. Being unskilled but kind of big, I was often able to hit hard enough; if I have anything to say about it, my kids are going to log plenty of hours in a boxing gym.
> unless he pulls a knife I carry a knife nowadays, after being in enough situations that came close enough to turning ugly that I wished I had one. I think, on general principal, that it's good for everyone to carry a weapon. A distant relative of mine who was born in the town we moved to had told me that when he was younger, in the 1940s and '50s, everyone had a gun in their jacket, "and you could tip your hat and be polite, or take turns shooting at each other." There's something to that, I think, in adult society. If there are no easy targets, if anyone you try to mug/terrorize/rape/attack/etc. can potentially end your life, then society is its own deterrent to crime. There are always irrational actors, of course, but if the crazy guy has a weapon, I want a weapon, too.