There's a great deal of evidence resulting in belief by American diplomats and those in the intelligence community that the future of Iraq very much depends on what Iran decides to do. The current "peace" in Iraq, which is not very peaceful, is a pause in which hundreds of Sunni men who participated in the U.S.-allied Awakening have been assassinated, either by death squads linked to the Iraqi ministry of the interior or Iran's intelligence service. This leads to the conclusion that the Surge has not created the conditions for permanent peace and the context exists for another flare up of violence, notwithstanding the recent, peaceful elections.
The American war in Iraq has created the conditions for Iran to become the major player in the region and it holds most of the cards in Iraq. Whatever the outcome, and it might be a major confrontation between the U.S. and Iran, it is Iran and its actions in Iraq and the bargain it forges with the U.S. that will be the force largely driving the future of the region.
The U.S. as Doctor Frankenstein has created its own monster. Let's see if it can be contained; or whether, as in Ms. Wollstonecraft Shelly's novel, events have turned and the Doctor has lost control.