This chapter elaborates the book’s theoretical framework. It proceeds in three stages. First, based on a microfoundational analysis of the incentives facing states and international bureaucrats, I make the case that the former are more liable than the latter to engage in opportunistic behavior that imperils institutional performance. Second, I flesh out the concept of policy autonomy, explaining how its different components provide the basis for gains in performance and why it cannot be reliably established and maintained through institutional design. Third, I explore the true origins of policy autonomy, elaborating the causal mechanisms by which (certain types of) operational alliances and governance tasks insulate bureaucrats against state capture. The chapter concludes by summarizing the framework’s observable implications at the macro and micro levels.