I think the way to win in Afghanistan is to bypass the corrupt central government of Karzai and go to the disaffected Pashtun, Sunni tribal chiefs and warlords. They dislike both Karzai and the Taliban. This worked for us in Iraq. We need surrogates to take some of the load and the central governmental army won't do. The Russians found this out.
We need to go back to the 'ghost war' approach that the CIA and ISI used during the soviet invasion, to coopt the afghani tribal leader. It is reported that the Pakistani ISI has good lines of communication with these same Pashtuns so the job wouldn't be that difficult.
The way we won in Iraq was to work with the Sunni Awakening and create jobs for the unemployed Sunni's by hiring them to keep peace. A similar strategy could work in Afghanistan.
Here is a blog by a Rand political scientist suggesting that the insurgency in Afghanistan is mostly confined to Pashtun areas of the country, which are dominated by tribes, sub-tribes, and clans that have historically been anti-central government. These people feel Karzai stole the election.
The Afghanistan debate raging in the United States has become hijacked by an obsession with American troop numbers. But this discussion misunderstands the subtle nuances of fighting a war in areas inhabited by fiercely independent Pashtun tribes, whose culture and traditions are under severe threat from the Taliban.
The current strategy rightly focuses on protecting the Afghan population. The U.S. counterinsurgency manual suggests that a force of roughly 20 counterinsurgents for every 1,000 inhabitants is necessary to secure an area. But it is a misunderstanding of counterinsurgency doctrine to assume that these numbers must be international forces or even Afghan national security forces. What's more, it reflects a troubling failure to understand Afghanistan.
The insurgency in Afghanistan is mostly confined to Pashtun areas of the country, which are dominated by tribes, sub-tribes, and clans that have historically rejected an intrusive Afghan government and permanent international presence. Khushhal Khan Khatak, a seventeenth century Pashtun poet and warrior, aptly noted that "the very name Pashtun spells honor and glory. Lacking that honor, what is the Afghan story?"
Pashtuns are predominantly conservative Sunni Muslims and are the largest ethnic group in the country...An effective strategy needs to facilitate a Pashtun revolt against the Taliban...Pashtuns have generally eschewed an intrusive central government in their areas, but most have supported a
government that serves as a mediator.
Path to a Pashtun Rebellion in Afghanistan