[As] Stephen Biddle noted almost immediately following [the publication of FM 3-24], much about the doctrine is politically naïve. When the United States wages counterinsurgency campaigns, it almost always does so as a third party acting on behalf of a host nation. And implicit in the manual’s assumptions is the idea that U.S. interests will be aligned with those of the host nation.
They almost never are, though.
Without a working, legitimate, and only mildly corrupt Afghan government, we will never defeat the Taliban. Just how likely are we to get that kind of government? I'm not optimistic.