Ethnic cleansing is one of the worst crimes against humanity. But if the massive migrations among all of the warring countries in the Middle East results in definitive, well-defined zones of Sunni, Shia, and Kurd, it could result in more stable countries in the end. Forced migrations always leave bitter hurts that come back to haunt the evictor. But when people are fleeing bombed out neighborhoods, perhaps where they end up will feel like a step up, or at least good enough to mute the regret.
But this would only work if the world at large does a better job at supporting refugees, planning resettlement, creating economic opportunities for migrants, including them in the host's political process, facilitating some assimilation, etc. The last thing we need is 50-year refugee camps like we have among the Palestinians. Just imagine 100 Gazas all over the Middle East.
I was imagining a peace process along these lines when I heard a BBC report about Eastern Ukraine last night. In that case, you can't "split the difference, cut the rebelling zones in half, and declare peace." My thought was if they split Donetsk and Luhansk in half - east and west. Anyone in the west side who favors the rebels can move to a town in the east side. They don't even have to leave their "home" province." Same thing east to west for loyalists. But "home province" is not the same as "home". That is why I question the viability.
I (we?) live in a culture where people move at the drop of a hat. When your ancestors have lived in the same town for 400 years, I can only imagine the difference in how it would feel. The end of Fiddler on the Roof comes to mind. The sad way that Tevye and his neighbors just accepted being moved out of their town by the Tsar's army and the sad-looking caravan of refugees that this caused.
Ironically, it was a weak parallel of this that led me to move to my studio apartment last year. I don't want to become attached to "stuff," enabling me to move whenever I want without too much regret.