For an in-depth discussion of the two "Achilles heels in the current strategy: Afghan governance and insurgent sanctuaries in Pakistan" see the CNAS report Responsible Transition: Securing U.S. Interests in Afghanistan Beyond 2011, by Lieutenant General David Barno (USA ret.) and Andrew Exum.
Comments
There is very little disagreement that the Taliban sanctuaries in Pakistan pose the gravest threat to Afghanistan.
According to the influential Bruce Reidel, if the U.S. strengthens Afghanistan and its army, it might force Pakistan to reconsider its support for the Taliban.
Right from its birth, Pakistan chose to forgo developmental opportunities to embrace jihad as an important instrument of its foreign policy.
Heres an analysis of Pakistans early evolution: http://www.southasiaanalysis.org/papers42/paper4138.html
Pakistan has been waging a multi-front jihad on India, while knowing that it is a self-destructive endeavor. This may be because Pakistan as a nation lacks a progressive vision.
Why does the esteemed Reidel think that Pakistan will stop doing what has now become its second nature - which is to back jihadist groups against its neighbors?