The Baker-Hamilton Report calls for a reduction in troop levels to 70,000 by 2008 "subject to unexpected developments." Since the guy in charge of implementing it issued more than 750 signing statements saying why he did not have to pay attention to those laws which don't happen to strike his fancy, we're rather confident in his ability to interpet the phrase "unexpected developments" a somewhat loosely. His resolution to do exactly what he wants and nothing else can be considered a bit of a forte.
But it's also important to keep in mind that American presence in Iraq is not limited to troops. Donald Rumsfeld's legacy to the Pentagon, a key factor in its gross mismanagement, was a passion for privatization that has seen many jobs formerly performed by the military outsourced to independent contractors.
The Pentagon had estimated that there were 25,000 government contractors in Iraq, but that figure has escalated dramatically and was recently revised to 100,000 (and that's not counting subcontractors). Rumsfeld's "war on the cheap" turned out not to be so cheap; there are now 10 times the number of contractors in Iraq as were there during the Persian Gulf War. If there are 140,000 troops currently stationed in Iraq, that means the number of civilian employees there — many of them doing jobs that used to be performed by military personal (who frequently trained their replacements) — is fast approaching the number of military personnel. It's also a contributing factor to the re-enlistment problem — why would someone settle for military pay if they can get six figures for doing the same job for a private company?
As Robert Greenwald's film Iraq for Sale ably demonstrated, many of these people went overseas into dangerous jobs because they thought that in doing so they were performing valuable services for the troops and supporting their country. To date 610 have died. There may be tension between military personnel who have to risk their lives to guard these much more highly paid contractors when they don't have appropriate armor themselves, but the Iraqis don't see any difference between American military or those who work for Blackwater. They're all running around their country with guns.