Your bolded text may as well be the Balkans in 1935. Substitute religious sects for communists and nationalists (and different religious sects), and we're seeing and age old pattern. Given the multiple civil wars in various regions of the world that are drawing the eye of old powers combined with the generally cynical economic outlook for so many people, I am fearful of war, although I think the prospects are unlikely. But, as we've seen in history, the unthinkable remains so until it happens, and all of a sudden it becomes reality.
Yes, certainly strife in the Balkans predates modern Europe by a long shot. I chose 1935, because some historians have said that Germany and the USSR at that time used local civil wars as a pretext for invasion, and that especially the Germans co-opted dissidents to fight on their behalf against hostile regimes. One can envision the same happening in the Mid East today (cough, arm and train the rebels, cough)