Over at The Corner , Jonah Goldberg responds to my column on lowering the drinking age by making a drug war comparison. He's right. If the drinking age were lowered to 18, more 18-21 year-olds would likely drink (on the other hand, 80% of underage drinking would be eliminated!).

And the comparison to the drug war is accurate, too. If all drugs were legalized tomorrow, there would almost certainly be an increase in use. And he's right that the law does effectively curb some behavior. There's a broader philosophical point regarding whether or not using the law to curb private behavior is a moral and appropriate use of government coercion, but let's put that aside for a moment. The inevitable rise in use that would follow legalization is a point proponents of drug prohibition often fault drug war critics for not acknowledging, though I really don't know of any critics who don't willingly concede the point.

The more appropriate response to "more users" argument is "so what?" A slight rise in the number of recreational drug users is only a problem if you believe that there's something inherently immoral and destructive about smoking a joint or snorting a line of coke--any worse, say, than downing a shot of whiskey or a taking drag off a tobacco pipe. The subset of people who refrain from drug use today out of respect for the law, but who might experiment with drugs should they one day be legal, probably isn't one we need to worry about becoming addicted in mass numbers, or committing crimes to support their habit (which probably wouldn't happen anyway if drugs were legal--how many alcoholics mug, burgle, or kill for gin money?). Unless you buy the "gateway" theory of marijuana, or the "instant addiction" theory about cocaine, both of which have zero scientific validity, I'm just not sure having slightly more overall users will have much of a negative impact on society at large.

The question, then, is what's the problem?

Many drug warriors get downright offended when you ask them that (I don't know that Goldberg would--he's historically ambivalent about the drug war). The problem for them is very simply that there will be more drug users. It's rather simple: Drug use = bad. More drug use = worse. Less drug use = success. For nearly forty years, these really been the only criteria for measuring the effectiveness of drug policy.

Let me give you two examples.

Over the years, drug warriors from William Bennett to John Walters to Karen Tandy (as well as the current DEA website) have defended the efficacy of alcohol prohibition. All three have called the experiment a "success," and the notion that it failed a "myth."

Why would they say that? The fact that Prohibition was repealed alone ought to say something about its "success."

But Bennett & Co. insist alcohol prohibition was a success because it reduced alcohol consumption. This assertion itself is debatable (see Jeff Miron's terrific research on the subject). But even assuming they're right, this line of argument is revealing. To call alcohol prohibition a "success," one would have to consider overall consumption of alcohol in America the only relevant criteria. You'd have to ignore the precipitous rise in homicides and other violent crime; the rise in hospitalizations due to alcohol poisoning; the number of people blinded or killed by drinking toxic, black market gin; the corrupting influence on government officials, from beat cops to the halls of congress to Harding's attorney general; and the erosion of the rule of law.

Of course, the 18th Amendment was passed because prohibitionists convinced the country that Prohibition would alleviate many of these problems. But once prohibition was in place--and still today among its defenders--it became not about externalities, but about preventing people from drinking as an end, indeed the only end. If it did that, it was successful. Never mind that it was exacerbating the very justifications for its enactment.

We see this today with the drug war. Which brings me to my second example. Last December, the ONDCP put out a triumphant press release celebrating a five-year decline in the use of illicit drugs among teens.

Teen drug use has declined by 23 percent since 2001 for 8th, 10th, and 12th graders combined, with reductions in the use of nearly every drug in every drug prevalence category, according to the University of Michigan's 2006 Monitoring the Future (MTF) study, released today. This translates into approximately 840,000 fewer youth using illicit drugs in 2006 than in 2001. These reductions represent a nearly exact achievement of President Bush's goal of reducing youth drug use by 25 percent by 2006. Reductions in illicit drug use among 8th and 10th graders exceeded the President's goal, falling 30 and 26 percent since 2001, respectively.

"There has been a substance abuse sea change among American teens," Drug Czar John Walters said in the release. "They are getting the message that dangerous drugs damage their lives and limit their futures. We know that if people don't start using drugs during their teen years, they are very unlikely to go on to develop drug problems later in life."

Note that all of this triumphalism is based on one set of criteria, and one set only: The number of teens reporting the use of drugs over a given time frame.

But this past February, the CDC reported that deaths from drug overdoses rose nearly 70 percent over the last five years. Half the overdose deaths were attributable to cocaine, heroin, and prescription drugs. The number of overdose deaths caused by marijuana--the drug most targeted by the ONDCP--remained at zero. And among the biggest increases (113%) were those aged 15-42, those same teenagers the ONDCP was celebrating in its prior press release.

To look at those two figures and conclude that the drug war is moving in the right direction seems to me to indicate a near-religious devotion to preventing recreational drug use, at any cost. Prohibition advocates are again measuring success not on how well the drug war is preventing real, tangible harm, but simply on how effectively they're preventing people from getting high.

And of course overdoses are only one aspect of the harm done by the drug war. There is also the appalling rate of incarceration in America, the evisceration of the Bill of Rights, the erosion of the rule of law, the government infringement on the doctor-patient relationship, the contempt for property rights, the arrest of promising developments in the treatment of pain --the list goes on.

Nevertheless, so long as there are fewer joints in teen backpacks, the drug warriors are content to say we're "winning."

Goldberg isn't a Bennetista-type drug warrior. His post was really just my jumping-off point, here. But getting back to his point, I'm not sure having a few more recreational drug users would be all that harmful, any more than having a few more drinkers would. And it certainly wouldn't be harmful enough to outweigh the considerably larger reduction in harm that would result from ending drug prohibition.