For the past week, along the eastern border with Pakistan, the eight passes that provide the easiest crossings, were being taken over by 2,000 Pakistani troops and tribal militiamen. This has been assisted by 500 US and Afghan troops on the Afghan side. All people and cargo will be examined to insure that no Taliban or illegal weapons cross. There are still ways to get across, but these take a lot more time (going up the mountains and ridges.)
Those Pushtun tribes that provided the core leadership for the Taliban still want to restore their form of government (based on keeping women locked up and illiterate and no entertainment or much education, and so on.) In Afghanistan, tribes often pursue their own ways for generations, despite the opposition of neighbors. The Pustun tribes in the south are still hiding former Taliban leader Mullah Omar and his associates. American Special Forces are slowly working their way into the relationships in these tribes and, eventually, where Omar, and Osama bin Laden, are hiding out.