I mean, I get it. The Pentagon spent last week whispering that it wanted pretty much no withdrawal from Afghanistan this year. The White House counters with a return to first principles: bin Laden dead, al-Qaeda wheezing like a fat jogger, when would be a better time to begin a substantial troop reduction? But this is just nonsense:
Fighting Al Qaeda, they noted, was the main reason Mr. Obama agreed to deploy 30,000 more troops last year, even as he adopted a broader, more troop-intensive and time-consuming strategy of making key towns in Afghanistan safe from the Taliban and helping the Afghans to build up security forces and a better-functioning government.
You don't send an extra 30,000 troops to fight al-Qaeda in a country where al-Qaeda isn't. Especially when you don't send most of them to the east, the part of Afghanistan abutting the place where it is. You send the reinforcements to salvage a faltering war that's deteriorated so much that its original aims barely appear on the horizon. Knock the Taliban out of the south; buy time for the Afghan government to do... anything; train Afghan soldiers and cops. Buy time and space for a measure of stability that favors the Afghan government and strengthens the resiliency of Afghanistan against al-Qaeda's return.
You can dispute the premises of most aspects of the strategy. But it has pretty much nothing to do with al-Qaeda reeling in the wake of bin Laden's death. The Afghanistan war is about a soft landing for Afghanistan now; and a launching pad (Bagram, Kandahar, Jalalabad, maybe Salerno) for strikes into the Pakistani safe havens. Afghan troops still need to be trained -- and kept from killing their U.S. trainers -- for instance.
Now, you can still draw down substantially without tearing up the strategy. But the most important benefit to leverage out of bin Laden's death is political: negotiating with the Taliban. See what's feasible for ending the war, with enforceable compliance mechanisms that ensure Afghanistan doesn't threaten the United States. That should drive military strategy -- finally. The military strategy is unmoored from any political strategy, and negotiating peace is the only political strategy that matters any more. That's not peace at any price. That's peace knowing what the price is.
Making al-Qaeda's weakness makes negotiation a much safer gamble, but to make it the criterion for taking troops out makes more sense if the strategy is simply to go, without setting the table for Afghanistan not to collapse in the wake of a withdrawal. (Though Afghanistan could still collapse!) Tethering withdrawal to a weak al-Qaeda only makes sense as a political gambit for reelection, and even then it'll come down to, "Trust us, we saw it in the bin Laden documents."
None of that is to say that the weakness of al-Qaeda in Pakistan doesn't impact the original and enduring rationale for the Afghanistan war. It is to say that the long deterioration of the war has compelled additional considerations as well. If substantial troop reductions can benefit those considerations, all to the good.