“The world’s ‘drug czar,’ Antonio Maria Costa, would have you believe that the legalization movement is calling for the abolition of drug control,” he said. “Quite the contrary, we are demanding that governments replace the failed policy of prohibition with a system that actually regulates and controls drugs, including their purity and prices, as well as who produces them and who they can be sold to. You can’t have effective control under prohibition, as we should have learned from our failed experiment with alcohol in the U.S. between 1920 and 1933.”

cannabisnews.com: UN Backs Drug Decriminalization In Drug Report.

Based on the fact that heroin use has dropped and overall drug use has NOT increased, it definitely did not fail. And some say it has succeeded.

via Drugs in Portugal: Did Decriminalization Work? – TIME.