Walt's "Safe Haven" Update

Professor Walt nicely posted his own response to Bergen's critique just a few minutes after my own. He reiterates his scepticism that the Taliban would actually regain control of Afghanistan, and discusses how useful a base Afghanistan actually would make for al-Qaeda. I still think he should discuss the existing safe haven in the tribal areas along the Afghanistan-Pakistan border, but no matter, he makes similar points as I do. I think the questions deserve to be asked, but the answer is not a cut-and-dry "withdraw" as Walt seems to be arguing.