Humpty Dumpty sat on a wall
Humpty Dumpty had a great fall.
All the king’s horses and all the king’s men
Couldn’t put Humpty together again
Much like the rhyme “Humpty Dumpty”, Iraq, now broken, cannot be put back together. Not with all the US military might, not with all the political finagling.
At one time it seemed a simple matter of partitioning Iraq amongst the Sunni, Shia and Kurds but now, even that will not be possible. The IS, the new player, having conquered bits of all three ethnic regions, will make that solution even more difficult.
Still, it is unlikely that Iran will allow the IS to absorb the Shia, and to prevent it would probably intervene full scale militarily to do so. Too, Saudi Arabia, bordering on Iraq’s Western Sunni region would not want the IS on its border.
The Kurds, militarily and economically more able and with Western support, will probably be able to withstand a takeover by IS losing only isolated cities.
Thus, we could have a major makeover in former Mesopotamia. A Syria based IS that slops over into northern old Iraq, a Shia State melding with Iran or as a semi-autonomous Shia state within Iran and a Sunni State reliant on and tied to Saudi Arabia.
In many respects this division would make more sense than the lines drawn in the sand in Paris in 1919 which totally ignored the historical regional ethnic-religious split.