I find the current use of the word "terrorist" to be very strange. It seems to be little more than special pleading; The western powers apply it liberally to their enemies, essentially to label them as evil, while not applying it to allied actors. For instance, the ongoing conflict in Yemen is causing massive harm to civilian populations, but the Saudian Arabian state has not been designated as "Terrorist". I am completely in favour of the establishment of tribunal to prosecute war crimes, but these should be based upon the well-defined and recognised principles of international law, not arbitrary labels like "Terrorist".