Here's more sense from the Brookings Institute:
Today, Congress, too, faces a pivotal choice on Iraq. The moment that Congress enacts a law constricting the president's freedom of action in Iraq, it buys a considerable share of responsibility for the war's outcome. Will tomorrow's narrative be that the strategic military situation in Iraq was starting to improve in 2007 but Congress pulled the plug anyway—emboldening Islamist extremists throughout the region and demoralizing all our friends? If so, perhaps it's not President Bush who needs political cover from his opponents but they who want political cover from him.
Quote Originally Posted by Seamus Fermanagh
According to Englehardt's numbers, we've got 156k US troops, 25k contractors, our allies, plus those Iraqi units that pass muster.

This means we're short and that the surge will be nothing but a shell game in the long run -- even though the effort to suppress Bagdad is having some effect.
You're forgetting the almost 350k of Iraqi security forces Seamus. Regardless, I have disdain for such a hard and fast "formula" that only implies one way to success- it's never that simple. You might say Gen Petraeus wrote the book on counterinsurgencies- if anyone can pull it off at this point, it would be him. Anyone know if the 10-1 type figures made it into his book?