Without U.S. forces in the country, there is a strong possibility Afghanistan could host a reinvigorated Taliban allied to a reinvigorated al Qaeda.

Keeping a relatively small, predominantly U.S. Special Forces presence in Afghanistan to continue to train the Afghan army past December 2016 is a wise policy that would benefit both Afghans and Americans.

It is in Pakistan's own interest that the Afghan army is able to fight effectively against the Taliban, which is more likely if they continue to have American advisers at their side.

Peter Bergen Quotes