As global governance appears to become more inclusive and democratic, many scholars argue that international institutions act as motors of expansion and democratization.The Closure of the International System challenges this view, arguing that the history of the international system is a series of institutional closures, in which institutions such as diplomacy, international law, and international organizations make rules to legitimate the inclusion of some actors and the exclusion of others.While international institutions facilitate collective action and common goods, Viola's closure thesis demonstrates how these gains are achieved by limiting access to rights and resources, creating a stratified system of political equals and unequals.The coexistence of equality and hierarchy is a constitutive feature of the international system and its institutions.This tension is relevant today as multilateral institutions are challenged by disaffected citizens, non-Western powers, and established great powers discontent with the distribution of political rights and authority.