At the same time, to claim that Iraq is even mostly about Al Queda is equally wrong and naive beyond belief. As a matter of scale, Al Queda in Iraq franchise is dwarfed by the sectarian violence going on now. Al Queda may well be our primary concern, but Al Queda is present in Iraq only because Iraq is teetering on the edge of becoming a failed state.
What will happen if we leave Iraq before we achieve complete victory?
Lurking behind this question is the assumption that "complete victory" in Iraq is still possible. Secretary Gates has indicated that it is, but it is a long-shot.
Now, we must remember that it is not "defeatism" to question the Administration's tactics, claims, strategies, or ideologies. We got into this mess because the Administration assumed, because we'd be greeted as liberators, that de-Baathifying the country would go as easily as de-Nazification went in Germany. Dissenting voices, like Gen. Shinseki, were marginalized and ballyhooed. Good faith questioning of the Administration's tactics is not "defeatism" or treason. It is loyal patriotism..
I don't know what your thoughts are about "once we leave" are but I think IRAQ will simply change it's last letter to N and we will be facing a middle east largely under the Iranian sphere of influence. I think it is safe to say that the conclusion will be a conflagration, probably nuclear. It may not occur this year, but shortly. Iran has to be addressed by the USA or by Israel and the clock is ticking. If we leave, we have no counter balance to Iranian expansionism. Iraq was the smart move, but following through with an energized 5th column biting at your heels will be a long shot.