This chapter takes three historical moments—the opium wars, the ‘war on drugs’, and the ‘war on terror’, and uses these episodes to demonstrate the various ways in which interests over opium are caught up in, interrelated with, and co-productive of, international legal regimes. In particular, the chapter focuses on the ways in which opium illuminates paradoxes around and within the concept of sovereignty, and specifically how opium as an object of international law has enabled interventions in sovereign states. Physical interventions in sovereign territory, economic interventions enabled by laws that concern both the facilitation and prohibition of trade, and moral interventions based on standards of morality and civilization are considered.