The ongoing opioid epidemic in the U.S. is just a glimpse of a complex ecosystem characterized by the interaction of multifaceted actors from various countries around the world cooperating across different stages of the global supply chain. In this book, 21 experts provide a comprehensive multidisciplinary analysis of the fentanyl supply chain, guiding the reader through the complex supply chain, the nature of criminal and state actors, and the linkages between different regions around the globe.