This situation is striking me as very much like that of the former Yugoslavia. Tito held Yugoslavia together by supressing ethnic rivalries, but when he died, it all started going poof. Bloodily.

I also cannot help notice that Iraq is one of those countries whose boundaries were somewhat arbitrarily drawn by colonial European powers after WWI. Kind of like Czechoslovakia, which also split as soon as it got at chance, although quite a bit more peaceably than Yugoslavia.