Consider this headline from today's New York Times:

Coordinated Bombings Kill at Least 101 in Baghdad

Does that sound like a country that has achieved peace and understanding?  And we still have over 100,000 troops there.   Not to mention that since the Iraq surge, violence has escalated in Pakistan and Afghanistan.

Once we leave (if we leave), civil war seems almost inevitable.  This does not mean we should stay; that just delays the inevitable, and at a large, ongoing cost.  But we should not kid ourselves about what will happen once we are gone.