This chapter provides an overview of U.S. criminal enforcement actions against global banks, including aggregate statistics about their targets and the penalties levied. It then examines the characteristics and motives of the principal actors involved: the global banks themselves, the regulatory agencies that supervise them, and the prosecutors who brought criminal cases against them. The chapter develops the book’s three central arguments, which structure the case studies examined in the following chapters. First, it argues that prosecutors bring to global bank oversight a set of priorities, incentives, and tools that differ fundamentally from those of the specialized agencies and transnational networks that traditionally occupied that field. Second, it contends that the U.S. government’s ability to impose its will on global banks stems from its control over vital hubs of the international financial infrastructure, such as the U.S. dollar and U.S.-based payment systems. Third, it argues that although U.S. enforcement actions have triggered complaints of unilateralism and can in some cases be self-interested, they can also unlock obstacles to international cooperation and lead to widespread benefits.