Interdiction campaigns attempt to seize drugs while en route to the U.S.; however they have been proven unsuccessful at reducing domestic drug use. Despite efforts by the Drug Enforcement Agency, U.S. Customs, U.S. Coast Guard, U.S. Army, and the Immigration and Naturalization Service, it is an impossible task to keep drugs from coming in through 19,924 kilometers of shoreline, 300 ports of entry and more than 7,500 miles of border with Mexico and Canada.

Mexico is the major transfer point for cocaine imported to the U.S.; although it originates in Colombia, it is estimated that half of the cocaine consumed in the U.S. enters through Mexico. Mexico also produces and exports marijuana, and to a lesser degree heroin. Estimates show that interdiction efforts only seize an estimated 10-15% of the heroin and 30% of the cocaine coming into the U.S. The governors of four Mexican Border States recently announced they will consider decriminalizing marijuana because the current efforts to interdict drugs at the border have not been successful at reducing drug use.

Anti-drug efforts in Mexico are impeded by rampant corruption and institutional weaknesses. Although Mexican leaders have pledged to fight corruption they have not been successful. The U.S. certification process, which determines whether countries that receive aid are sufficiently in line with U.S. drug policies, is a source of contention in U.S.-Mexican relations. Many people see this process as hypocritical because the drug trade in Mexico is largely driven by U.S. demand, yet the failure of punitive U.S. drug policies to reduce drug use is blamed on Mexico.