Duncan - I do not think we have to fear ISIS/ISIL in the long run for they are cowards and not actually convinced in their own cause. Why you may ask. If they deep down believed their own presentations they would not hide behind a mask. Those that believe in themselves and their actions are not afraid to show their face.
"Cowards die many times before their death. The valiant taste of death but once." - ShakespeareArt SegerDuncan