The research project proposed here concerns cooperation between American and Mexican law enforcement agencies in combating the threat posed to both countries by Mexican drug-trafficking organizations (DTOs). Its broad goals are to assess the current status of cooperation, identify obstacles to cooperation, and formulate practical policies to improve cooperation. To achieve the project's goals, the project team will conduct two rounds of in-depth, semi-structured interviews of American and Mexican stakeholders. Stakeholders are government officials working in bilateral, federal, state, and local capacities, non-governmental organizations (NGOs), and journalists or other experts. The interviews will be conducted in Washington, D.C., Mexico City, and the "paired" cities of San Diego/Tijuana and El Paso/Ciudad Juarez. The interviews are designed to (1) assess current cooperation between U.S. and Mexican law enforcement officials and establish a baseline for assessing change in the extent and effectiveness of cooperation; (2) identify the major obstacles to effective cooperation between American and Mexican law enforcement agencies; (3) evaluate the impact of these obstacles in realizing the mutual goal of reducing drug-related crime on both sides of the border; and (4) produce information to formulate more effective and practical criminal justice policies. ca/ncf