Lots of people when they look at martial arts want to learn to fight. I prefer to think of a martial discipline as learning 'not to fight'. Heightening our awareness to situations can save a lot of trouble in the long run and the easiest way to stay out of trouble is not to go where trouble is. Sometimes when you go out and walk into a pub or club you get a feeling of unease, like something could 'kick off' any second - this is your trigger to leave and not be around such energy. It is much better to know when to walk away and when to stay. I know you are going to say sometimes you have no option but the truth is if you learn how to read that negative aggressive energy before anything happens you cut down the risk immediately of becoming involved in a violent situation.
I like to teach the Martial aspects of Tai Chi but at the same time I like to emphasise how easy it is to hurt someone with such techniques and also get hurt - there is no glory in fighting so learn to walk away when you can!!!