For many students of global governance who explore the myriad institutions, rules, norms, and coordinating arrangements that transcend individual states and societies, what really marks the contemporary era is not the absence of such governance but its “astonishing diversity.” In addition to “long-standing universal-membership bodies,” such as the United Nations, writes Stewart Patrick, “there are various regional institutions, multilateral alliances and security groups, standing consultative mechanisms, self-selecting clubs, ad hoc coalitions, issue-specific arrangements, transnational professional networks, technical standard-setting bodies, global action networks, and more.” The proliferation and diversification of governance mechanisms—yielding a jumble of formal and informal arrangements—has supplanted the simpler image of state representatives gathering at official assemblies. Many scholars believe this pluralism opens important new avenues for tackling a growing array of complex transnational problems, particularly at a time when the responsiveness of traditional multilateral institutions is being called into question.