If you actually read the treaties, while they do set firm limitations on the legal, "non-medical" or "non-scientific" sale of schedule drugs — limits that Uruguay, Colorado and Washington ignored when legalizing cannabis — they don’t otherwise obligate countries to penalize drug use. Even the 1988 convention, the harshest of the three, which instructs countries to criminalize use, still provides an out for states, allowing such laws only as they are "subject to its constitutional principles and the basic concepts of its legal system." This loophole has been used by the Dutch to argue legally for their coffee shops.
In its 2006 World Drug Report, the UN Office on Drugs and Crime (UNODC) struggles to construct success stories to convince the world that the global drug control regime has been an effective instrument. An escape-route used in this year's World Drug Report is to fabricate comparisons with higher opium production levels a century ago and with higher prevalence figures for tobacco.
The UN's top narcotics official said on Wednesday that recent votes by US states to legalize marijuana have put America in deeper violation of the international conventions that guide drug policy around the world. Earlier this month, voters in Oregon, Alaska, and Washington DC legalized the recreational use and sale of marijuana. Similar ballot initiatives have already passed and taken effect in Colorado and Washington.