Drug enforcement and drug consumption. No relationship?

From libertarian drug policy expert Jacob Sullum:

With the U.S. Drug Enforcement Administration celebrating its 35th birthday this week, the publication of a new study estimating drug use rates across countries is well-timed. Of the 17 countries surveyed by the World Health Organization, China has the lowest rate of illegal drug use (cannabis and cocaine combined), followed by Japan, while the United States has the highest rate, followed closely by New Zealand. (Here is a comparison table.) "Globally," the researchers report, "drug use is not distributed evenly and is not simply related to drug policy, since countries with stringent user-level illegal drug policies did not have lower levels of use than countries with liberal ones." It may be that the United States has especially stringent drug policies partly because it has especially high levels of drug use. But it seems clear, after you look at drug use not only across countries but over time in the U.S., that the ebbs and flows have little to do with the intensity of drug law enforcement (which is not to say that prohibition itself has no impact).

...

Getting back to the WHO study, it's striking that the lifetime marijuana use rate in the U.S. (42.4 percent) is more than twice as high as the rate in the Netherlands (19.8 percent), despite the latter country's famously (or notoriously, depending on your perspective) tolerant cannabis policies. The difference for lifetime cocaine use is even bigger: The U.S. rate (16.2 percent) is eight times the Dutch rate (1.9 percet). Do these results mean that draconian drug laws promote drug use, while a relatively laid-back approach discourages it? Not necessarily; that would be a hell of a "forbidden fruit" effect. But one thing that's clear is the point made by the WHO researchers: Drug use "is not simply related to drug policy." If tinkering with drug policy (within the context of prohibition) has an impact, it is hard to discern, and it's small compared to the influence of culture and economics.

As one of the commenter points out, his focus on drug policy (in this post, anyway) is limited to policies related to legality of use and possession--not access to treatment or other demand reduction efforts.

Also take the time to check out his post from the previous day. It reviews the undeniable lack of progress in high school drug use since the inception of the DEA.