How is that any different than the previous divide where saudia arabia and iran feared iraq? Sure there may be minor differences about the seriousness of the threat, and the borders of which country fears which country is different than it was before, but overall big picture business as usual in the mid east.
The problem about the current mess is there are no clear cut borders. No its just anarchy, killing, and the possibility of an even larger civil destruction/chaos/ethnic attrocities (not a civil war for civil war need political entities, no its far worse the death and mayhem of a civil war without knowing who side you are on).
1.6 to 2 million people have fled Iraq since 2003 to neighboring countries (that is .07 to .09 percent of the country if that many people left the us it would be 21 to 27 million people). By this many people fleeing you risk the chance of spreading this chaos to neighboring states. Furthermore such chaos generates more radical people such as terrorists who use things such as bombs to kill civilians and try to overthrow governments, there is a chance that circumstances may change and they now use those same skill against other targets.
I can go on, but I don't have the energy to do so.
