And these are all things that will go into the decision of attempting to stop him or not. Personally, I always, always have a knife on me. If I believe that the guy is carrying a weapon maybe I won't intervene. If I think he can take me down then maybe I won't, its obviously a situation by situation thing. How is it immature or naive to assess the situation (including the person involved) and come to a decision of weather you can stop it or not. You don't have to get involved if you don't want to, why is it such a big deal for you if I would?
Who the hell are you, John Lock?
Dude, lol, you can't "assess" a situation like that. You can't figure out on your own if a guy is packing a knife or a gun or something worse just by "glancing" at him, I mean, how are you going to figure that out? The only way you can figure that out is if you ask the guy. Or attack him. And by that time, your life might be over because you are bleeding internally.
And no, it doesn't really matter to me if you would. I'm saying it's stupid, because it is, are you a trained fighter? A trained policeman? Probably not, so let them do the job, you know, the guys who are trained for it. You're just asking for trouble.
And at this point in the conversation there isn't really much else to be said, on my part.