Within a conceptual framework of intercultural relations, the author considers the history of the transcultural spread of substance-use behaviors and possible reactions to the introduction of new drugs within a culture or jurisdiction, including illustrations of the "law of alien poisons." This refers to cultural adherents' tendency to view drugs from abroad as being more disruptive, deleterious, and dangerous than those native to one's own country. Although intercultural views of substance use have generally focused on majority groups' views of substance use in minority groups, minority and non-Western views of substance use should be considered in the context of increasing international and intercultural communications that increase the rate at which substance-use behaviors spread. Both Western and non-Western experiences with substance use and misuse must be taken into account so that better interventions can be developed to deal with addictions and other substance-related problems. 3 tables and 68 references