Is the drug war being won in Mexico? How can success be measured? This study argues that evaluation of multiple measures over an extended time period is required to gauge success. However, current US analysis evaluates Mexican presidential administrations and their efforts primarily on a year-to-year basis. As a result, US assessments tend to link lack of success to the Mexican government and its actions or inaction. Long-term evaluation, though, reveals that Mexican administrations have adopted most of the drug war strategies and tactics advocated by the US. These policy recommendations, though, have not proven successful. There has been no sustained reduction in drug purity, no permanent increase in drug prices, nor any long-term decrease in drug use in the US. This broader, more extended evaluation calls into question the possibility that a supply-side approach can ever be successful.