In 1961, more than 186 parties representing the world’s governing bodies signed on to the Single Convention on Narcotic Drugs. The convention is essentially an international treaty to prohibit the production and supply of specific narcotic drugs. And under heavy U.S. pressure, the Single Convention placed the same restrictions on cannabis that it did on opium, listing marijuana as a Schedule IV drug. As defined in the treaty, Schedule IV designates a category of substances considered to have “particularly dangerous properties” in comparison to other drugs and to be “particularly liable to abuse and to produce ill effects.”
