Latin America has emerged at the vanguard of efforts to promote debate on drug policy reform. For decades, Latin American governments largely followed the drug control policies and programs of Washington’s so-called war on drugs. Yet two parallel trends have resulted in a dramatic change in course: the emergence of left-wing governments that have challenged Washington’s historic patterns of unilateralism and interventionism and growing frustration with the failure of the prohibitionist drug control model put forward by the US government.