This submission has been removed because it involves current events. To keep from discussion of politics, we have a 20-year rule here. You may want to try /r/ask_politics or another current-events focused sub.

To be clear, in order to make a comparison between current events and historical ones, the current events must first be assessed and contextualized, which historians have not yet had time to do. If there are certain characteristics of ISIS which you can specify yourself as examples that could help. Do also consider specifying the area of the world you are interested in.