The problems associated with drug abuse in the United States have received considerable attention in recent years. By the mid-1970s, approximately 500,000 Americans were addicted to heroin, while at least 15 million were regular or casual users of marijuana. None of this heroin originates domestically, and only a small percentage of the marijuana, and this of low potency, is home-grown. Consequently, the question of source has become cardinal to most analyses of drug use and abuse in the United States.

Mexico has long been the primary source of high potency marijuana for the American market. Despite the recent influx from Jamaica and Colombia, Mexico still supplies an estimated 70% of the annual American consumption, or some 10 million pounds. More importantly, Mexico is currently the source of 70% to 80% of the heroin on the U.S. market, an alarming 6-8 ton annual figure. Furthermore, Mexico is both a primary transshipment route for cocaine, an increasingly popular drug originating in South America, and the source of vast quantities of psychotropic substances.