Think...
..why would Obama backpedal on Iraq if the US were NOT experiencing a MAJOR benefit? Especially when the core of his supporters are mouth-foaming opponents of the US presence in Iraq?
He knows now the way the land lies and is reversing himself before the election, so, if elected, he can late tell his supporters that he DIDN'T break a pre-election promise. He's confident enough that those votes will not be going to the man the left have portrayed as "Mr. 100 years."
No, he wants to preside over a hopeful recovery not a full fledged depression. He will keep the US troops and our contracts for Iraqi oil.