Is the new tobacco regulation law a model for drug legalization?

William Saletan think so. The gist of the argument he makes in that Slate article is: the tobacco law Obama just signed aims at "harm reduction" through regulation rather than outright prohibition of tobacco products; therefore, we should do the same thing with currently illegal drugs. Though he doesn't mention any specific illegal drugs in his whole article about them, I presume he'd like to see marijuana, LSD, cocaine, and even heroin legalized and regulated.

Here are a few of my half-formed objections to this analogy:

1. The regulation is dealing with the pre-existing problem of tens of millions of Americans being hooked on cigarettes. Of course Saletan is right that you couldn't just prohibit them and turn all Americans, or even the vast majority, into non-smokers overnight. But why is it that so many people are smokers already? A big part of it is that cigarettes are legal. The fact that something's illegal makes it a lot costlier to engage in; thus, many people will choose not to do it because, even without any sincere moral qualms about using drugs or even breaking the law, they simple aren't willing to bear the costs (which include paying more money, risking legal consequences, etc.).

If you read Saletan's article, you'll see that he's very skilled at creating a sense that anyone thinking rationally about the situation must conclude that legalization/regulation is the solution to America's drug problem. But this is far from obvious, and it's really hard to test the theory without actually putting it into practice. I'm sure that heroin could be regulated to be less harmful, and that this would benefit some people -- but since it could also lead to some people using heroin who wouldn't have done so otherwise, it's not clear that there would be a net benefit. Somewhere along the line, you'd be sacrificing one person's health (the person who gets hooked on legal heroin but would never have touched illegal heroin) for someone else's (the current junkie).

2. It's easy to take this moment in 2009, right when this law is signed, to point out how rational it is. But you can't assume that if drugs were legalized, they'd be well-regulated right off the bat. The federal government first officially recognized the deadly nature of cigarettes in 1964; it took decades to get to this point.

3. Saletan seems to assume that the new regulations will be effective. I hope they are, but it's good to be cautious when predicting the consequences of a radical change in the law that's ultimately aimed at changing human behavior. As one of the commenters on Saletan's article points out, there are already "mild" and "light" cigarettes, and they've been empirically shown to cause as much harm as non-light cigarettes. That's because, while they may have less bad stuff per cigarette, smokers compensate by smoking more of them, or smoking each one more intensely. It's hard enough to predict the effects of regulating cigarettes; why should we assume that drug regulation would be effective? Even if the regulations are intelligently written, swiftly enacted, and vigorously enforced (all of which are open to question), how do we know that purer, safer drugs wouldn't encourage people to use more of them? And any regulation that makes the drugs milder could lead to the same compensating behavior as with light cigarettes -- again, increased use.

This is all wild speculation on my part; I might be wrong on many of these points. Supporters of legalization, on the other hand, often try to create the impression that they know regulation would be effective. I don't think anyone knows that.