Bill,

I don't think the Taliban ever really eliminated the drug trade, although they did make it more inconvient for a while. I have seen some reports that they actually found a way to profit from the trade.

If it were true that the enemy did not profit from the drug trade, then it might be cost effective to just buy the drugs and take them off the market or sell them to pharmaceutical companies. My speculation is that people who grow and sell drugs do not have many inhibitions and therefore, they are likely to be dealing with other people without inhibitions including the enemy.