During 2000-1 in Afghanistan, the Taliban achieved a longtime goal of national and international drug policy agencies: a large, sudden, and unanticipated reduction in world opium production. This cutback provides an unprecedented opportunity to study the dynamics of the world opiate market andask whether further interventions could effectively reduce the flows of drugs. Based on an extended, multi-national study, the authors construct a new model for the trafficking of drugs and revenues and offer the first account of the world market in heroin and other illicit opiates during and afterthe 2001 ban. The authors' broader findings demonstrate how robust production, trafficking, and consumption combine to make successful long-term interventions on the supply-side rare exceedingly difficult, though specific policies can impact the organization and behavior of markets. For reductionsin both production and consumption, where the cultivation of opium is entrenched in the normal life and legitimate economy of millions of people, international agencies and foreign governments must provide adequate and long-term support to foster both alternative development policies and lawenforcement programs.