I've said it once and I'll say it again, no functioning, safe government/nation (as seen in American eyes) will ever exist in the current area mapped as Afghanistan. To try and prop up a pro-US government that is extremist free is an exercise in futility; ask the British, ask the Russians, shit look at the past ten years and ask yourself. And the whole as many boots on the ground as you can get and bomb the shit out of everything approach doesn't exactly make too many friends either.