Unless both Christian rooted countries and Islam rooted countries come to an aggrement and cooperation this will not stop i guess. Because even though every country aggree that these groups seem a brutal ruthless threat to the world, countries take advantage of the situation these terrorists create. For example Russia says they fight against ISIS but they cover their real intention that what they want to support assad syrian leader and their long historical aims of reaching mediterrian sea. Iran in response taking advantage of this group in order to cover their support to shia population and trying to arm them and take advantage of after asad situation in Syria. And all europe is doing to avoid humans migration who fled from war torn cities to safe areas. And like that everyone seems to enjoy the situation's opening them to advance and fullfill their hidden agenda goals. United nations seem inefficient in such situations sadly. Actually what we see as individuals in the picture of Syria is not shared by states and goverments they dont approach it as a humanatarian view but in respect to their benefits and what they can make out of this situation for their profit.