I do not condone violence and I do my best to avoid it whenever possible; however, I have been in many fights and I can think of only one that I believe was not justified.
I was raised with two younger sisters and my father has always told me that it was my job to protect them and to stop anyone who might threaten them. My parents said this of not just my sisters but of my family and as I grew and this became one of my characteristics I placed my protection on my friends as well. This was very common in my family among my relatives and my cousins and I always defended each other. This does not mean we are like a gang going around beating people up but rather the opposite. We feel safe around each other and that gives us a greater sense of freedom because we never fear violence.
When an older bully at my school would not stop harassing me and school authorities did little to stop the abuse my father taught me how to fight properly so that I can be more effective at stopping some one quickly and efficiently.
I have never gone into violence easily. In over 34 years I can still count with the fingers on my hands how many times I have been in a fight that was not for sport. I can almost always win a fight with my brains and I have learned to use it effectively in that way. But there are those who would resort to violence because they lack the intelligence to defend themselves without it. I refuse to be a punching bag for those people and I will fight back and hit them hard and effectively.
Quick, humorous martial arts story... We were at an international conference in New Orleans. 5 instructors, including 2 masters (5-7th degree) and a grand master (8-9th degree) were a part of the 5 walking. They were approached by 3 individuals, wielding knives. The instructors politely and quietly said that they were not going to give up their wallets, and asked them to let them pass. They attacked, and were immediately disarmed and detained, while the police were called. The only ones engaged in the defense were the masters/grandmaster (the three assailants attacked them first because they were older - all in their 50s-late60s).
Should they have handed over their cash and valuables? Tough call - and I think the call would be dependent on the situation. How many assailants? What weaponry? What mindset (e.g. pissed, in control, sad, in a rage, etc.)? Can you avoid the situation without harm, definitely? All of this weighs on you when you are considering a response, and you must make these assessments very quickly. In the case of this particular attack, the assailants were outnumbered, scared and antsy, were not wielding a firearm (although sometimes even that can be diffused), and were young. So, it was a safe bet to stop them before they hurt someone else, or are hurt themselves.
In that situation, with that group, I would have made the same decision.