Is this solution too simplistic? I don't think so. Crime flourished, gangs proliferated and many died as a result of poisonous home made bathtub liquor during Prohibition. The "war on drugs" is ineffectual and has cost billions of dollars. Afghanistan's blood money would dry up and they would no longer be such a threat to western civilization if there were no profit to be made.
It would require a an arduous campaign to educate Americans to understand that we have not all been corrupted since we can drink alcohol legally, and that the "Drys" were the ones who caused the racketeers to flourish during the days of Prohibition. However, it is worth the effort. It would certainly be less expensive than a continuation of war.
More troops sent into Afghanistan is not the answer, just more dead kid sand more wasted money. No one has been able, in the history of the world, to undo that country, and many have tried it, the latest being Russia.
Is it not time to try a completely new approach?