Put a better government into Afghanistan - or, better still, find some body or coalition in Afghanistan (including its diaspora and refugees) which is acceptable to the majority there, and not mutually abhorrent to/by the rest of civilisation... something moderate by Islamic terms, perhaps, but with stong Muslim elements: basic guarantees of freedom, equality, education: and some economic outlet not involving guns or opium. Help rebuild the country, without particular ties or requirements of allegiance, and I think this will work in the longer term.
Basically something similar to what was done in Germany, after WWII. Hopefully less expensive, since the expectations should be lower: but involving and boosting what moderate elements in Muslim/ME opinion can be found. Give guarantees of protection and non-interference, policed perhaps by Russia, NATO, Iran, Pakistan and Saudi, monitored by UN... turn the place into a beacon rather than a pyre.
Or is that rather too optimistic? |