When Do People Choose Tribalism?

When do people choose o tribalism? This certainly struck out at me when ugaslavia fell apart. They had pretty much forgotten that they had ethnic problems. That's not the way the world works. So my basy an up dating from the ethiopia events is to assign a greater role to contingency and to down grade the relevance of structure. I'm more inclined to think they had some very bad luck. A number of breaks went the wrong way. It might have continued, and may depend on individuals, a may just depend upon a few bad choices. You know, i'l be made. And what roll do these sort of thes thesea characters and individuals play