Washington’s goals officially remain those stated by Secretary of State Hillary Clinton: to strengthen Afghan Army forces and to “reintegrate” the supposedly “moderate” Taliban, that is, fighters who will consent to lay down arms and respect the Afghan Constitution, including its Western-inspired provisions to respect human rights and equality of women in the public sphere. Yet in nine years of war, no significant group of Taliban has opted for reintegration (a few individuals have come in, only to return to the Taliban when it again was in their interest). Moreover, coalition military personnel know that there isn’t a single Afghan Army brigade that can hold its own against Taliban troops.
From How to Turn the Taliban Against Al Qaeda – NYTimes.com
Of course, the best thing we could do is promote a war between the Taliban and Al Qaeda. Possibly pulling Pakistan into it. That’s awful. And many people would suffer. But it would be in the US interest to do so.