Sheesh robomatic! We are going to have a very long thread if we start debating that one! I would like to look at the problem of "fanatics" from another angle. Let me describe terrorism, for the sake of argument as "low level acts of extreme violence (compared to military capability) in support of a group, which exists outside of normal political structures". Now we describe most of the perpetrators as "fanatics" or "extremists" when they commit violence. Usually, in terms of real influence or power, they are very weak. So I think that terrorism is essentially an an act of despair or desperation by those, who feel they are under threat or that they have no other way of making their voice heard. That does not excuse it or make it any less despicable.
What gives me hope is that if you take soldiers off a battlefield, they can usually talk to each other and engage in real dialogue. If we can bring Hizbolla, Hamas etc into dialogue, they will not be able to see us as only a threat.
To go back to your final question. I suppose if we have a sudden flare up, and I swing a punch at your head, you have every right to limit your tolerance and to stop me from hurting you. However, we both know that when tempers have calmed down and we both listen to each other, we can laugh it off and move on. Dialogue can be long and tortuous, but the alternative is an eternal circle of atrocity and revenge. There simply is not any future in it.