That's the drug problem distilled to half a sentence. The market will supply demand, somehow, someway. The only way to block supply is to make it very, very expensive, in legal consequenses to the suppliers.
But that's impossible with our commitment to civil liberties and the restraint we put on law enforcement in the pursuit of those liberties. I recently watched an HBO series called 'The Wire'. One of the sub themes that became evident was the difficulty in convicting people that are involved in the drug trade. It's darn near impossible, and as soon as they get one person, two more take his place.
You can't stop the suppliers, you can't stop the cultivators, so the last decade or so has seen an effort to come down hard on the users. Now we have a prison system that is overloaded with people that serve serious time for simple possession. What effect has that had?
None. I'm starting to think there is no solution.
Maybe there is........shhhhhhhhhhhh.......whisper.......legalization?