This report is the work of the James A. Baker III Institute for Public Policy’s Drug Policy Program, led by William Martin, Ph.D., the institute’s Harry and Hazel Chavanne Senior Fellow in Religion and Public Policy. In addition to the sources listed in this paper, along with many other published books and articles, this report has benefited greatly from continuing dialogue with Professor José Luis Garcia Aguilar at the University of Monterrey, and with retired DEA intelligence chief Gary J. Hale, now head of the Grupo Savant think tank, and from interviews, mostly on condition of anonymity, with present and former agents of the DEA, the National Drug Intelligence Center, the FBI, and the Border Patrol. These are referred to in the paper as “observers” or “sources.” The program has recordings of all of these interviews.