On the way to the Oval Office before the Petraeus meeting, Biden asked Obama if beginning a significant withdrawal was a presidential order that could not be countermanded by the military. The president said it was.

Petraeus has immense stature, of course, and after the firing of two commanding generals in a row (Gen. David McKiernan was relieved in early 2009), Obama can’t get rid of him without a firestorm. But the general knows that with Afghanistan already the longest war in American history, he has only a small window in which to combine military force with creative diplomacy in a way that yields real improvement on the ground. If he can’t do it fast enough, the president will conclude that 100,000 troops actually harm progress by making the U.S. look like occupiers. At which point he’ll revert to the Biden Plan—kill Al Qaeda operatives with drones—and forget about Petraeus’s theories of counterinsurgency.

The country simply cannot afford a trillion-dollar commitment to nation building. The only way funding will continue much longer is if Republicans take control of Congress this fall. Even then, the war remains unpopular with the public, a point that won’t be lost on the GOP (as RNC chair Michael Steele’s antiwar comments last week attest). And Obama is hardly oblivious to the electoral implications. Let’s say that Petraeus insists that the July 2011 timeline be pushed back a year, which is quite possible considering the current problems on the ground. That means the de-escalation—and the political windfall—will begin around the summer of 2012, just in time for the Democratic National Convention. In other words, Americans should get used to it: we ain’t staying long.