Posted a bit too soon.
Basically, Andy, I think that we have a much better chance of fixing the drug problem in the US if we stopped treating it like a criminal issue and started treating it like a public health issue, which is what it really is.
Bad behavior (such as drug abuse) is not caused by bad incentives - it is caused by a lack of virtue: which is to say that it is a human failing. People are not perfectable. Ideologues of the Left believe that they are - and that Government ought to be the agent of perfection. Ideologues of the Right (insofar as many exist these days) demand that State power be used to impose morality by criminalizing "bad" behavior, or any behvior of which they disaprove .
Our Founders rejected these extremes because they knew that a free people could maintain their freedom only through the practice of Virtue. The role of Government in this regard is to promote such virtue, in part by protecting citizens from damage to life and property caused by poor behavior and by directing the mediating institutions of society (families, neighborhoods, churches, synagogues, businesses) to police themselves and their members. In the absence of self-corrective action, however, Government must act where threats to life and property become imminent and irreversible. John Locke (for one) recognized this police power as a necessary evil in a democratic Republic, but one that must be exercised for the purpose of maintaining public safety and and an orderly society.
We have today a substantial number of people living in this country who do not possess the personal responsibility, much less the knowledge, to live productive lives. That problem cannot be solved by Government alone - after all, it was Government that helped cause it. And having assisted in the development of such pathologies as drug abuse, the Government must now shield the innocent from them - at least until Virtue is rediscovered by those in most in need of it.