Congratulations!! You've just provided the answer to the diversity problem in Iraq!! Put good policies into place.
You know, as a student of American history, that heterogeneity does not, of itself, lead to Balkanization. You yourself said policy can make a difference.
The outcome, (whether Balkanization takes place or not) depends on how the heterogeneity is handled.
BTW, I've got to think a little more about the competing notions that
Unfortunately, Iraq was Balkanized on the day it was invented by the Brits (you remember them, the last significantly hubristic nation).
Here's the limit on my "help" in this debacle.
If we had been serious in efforts to establish anything but a puppet state, we would have chosen to help establish a Republic (Not so different from our own blueprint).