Portugal admitted locking everybody up wasn’t working, and shifted to treatment and prevention:

Five years later, the number of deaths from street drug overdoses dropped from around 400 to 290 annually, and the number of new HIV cases caused by using dirty needles to inject heroin, cocaine and other illegal substances plummeted from nearly 1,400 in 2000 to about 400 in 2006, according to a report released recently by the Cato Institute, a Washington, D.C, libertarian think tank.

“Now instead of being put into prison, addicts are going to treatment centers and they’re learning how to control their drug usage or getting off drugs entirely,” report author Glenn Greenwald, a former New York State constitutional litigator, said during a press briefing at Cato last week.

Under the Portuguese plan, penalties for people caught dealing and trafficking drugs are unchanged; dealers are still jailed and subjected to fines depending on the crime. But people caught using or possessing small amounts—defined as the amount needed for 10 days of personal use—are brought before what’s known as a “Dissuasion Commission,” an administrative body created by the 2001 law.

Of course, if we did that in the U.S., we’d probably have to close quite a few prisons.