Billmon:
More likely, this is part of some half-hearted, fumbling effort to peel away the Taliban "moderates" and "bring them into the process," like the attempt to bring the Sunni into the big tent in Iraq — a ploy which, we now know, almost worked too well.
Either way, I think we can take a guess at the larger motive: To shore up (or at least simmer down) the Afghanistan front in advance of the attack on Iran.