Pervez Hoodbhoy was at Hampshire College recently for the Darwin & Evolution in the Muslim World conference. However, a day before the start of the conference, he gave a lunch talk, Can the Taliban win in Pakistan and Afghanistan? The answer to this question now largely depends on the US decision about troops. While Pervez has been an anti-war activist all of his life, he made it quite clear that the US should not withdraw troops from Afghanistan. Such a move would be a morale booster for the Taliban - both in Afghanistan and Pakistan - and it will lead to a major turmoil in the region. In fact, his main point was that even if the US leaves right now, it will have to come back - and when it does - it will find the situation much messier than it is right now. I think he is right - the current Afghan war has now become a war of necessity.
Echoing these views, here is Ahmed Rashid on Fresh Air. This gives a good idea of the over all situation in Afghanistan. Regarding the destabilization of the region, listen to his answer about 34 minutes into the interview. Also, check out his article, The Afghan Impasse, in The New York Review of Books.