In "Myths About High Times in America" that appeared in the Washington Post, Ryan Grim discusses the 5 myths of drugs and drug use. Perhaps most interesting is number 4:
4. In foreign countries, legalization has been disastrous.
First, no country has ever completely legalized drugs, not since global treaties were signed a century ago ushering in prohibition. In Holland, drug laws are still on the books, but a social pact between the government and the people keeps shops from getting busted.
Portugal became the first European country to abolish drug laws when it repealed criminal penalties for pot, cocaine, heroin and methamphetamine in 2001. The world freaked: The United Nations suggested that the new law could be a treaty violation and would lead to crime, a spike in addiction and a rise in "drug tourism." But the country didn't fully legalize. People caught with drugs still had to go to a magistrate and face a small penalty. But they wouldn't go to jail.
Now the United Nations is lauding Portugal. In its most recent World Drug Report, it says, "These conditions keep drugs out of the hands of those who would avoid them under a system of full prohibition, while encouraging treatment, rather than incarceration, for users." The report also noted that the policy had not led to an increase in drug tourism and that "a number of drug-related problems have decreased."
The UN World Drug Report (available here) gives a full overview of the International Drug Market since 1909 when the international community met to discuss the Shanghai Opium problem. Given that Congress has several bills to consider how we are dealing with drugs in America, the report has some interesting charts and statistics.