No one wants to wilt away in a corner. The second line of defense is the mouth. Ninety percent of the time, you can talk yourself out of a situation. The third line of defense is cunning. The undisciplined provoker of fights is rarely very bright.
Confidence is the fourth line of defense.
If you know your stuff, others sense it. Only when these things have failed is violence permissible, and only the minimum required for the situation. Over the years, I've run into a handful of situations. I managed them rationally. For myself, running was never an option.