If I really understood terrorists I wouldn't be here now... Well, as the name says, they use "terror" as a sort of war strategy: nobody can predict what will they do, when/where will they attack and how, so everybody is afraid and this is the aim. If you want to be unpredictable, yes you have to hurt also the ones who agree with you, the innocent ones too, even yourself (kamikazes). This is horrible just while writing it, I'm feeling like if I drunk some poison for each of these sentences; so sorry I don't have any more answer. The only truth is violence and war are completely wrong, whatever is their form, and that's all.