Global power structures are changing. The United States and Europe are losing ground, as countries such as China and India increase their global reach. At the same time that new global players emerge, multinational corporations, global civil society organizations, and international media carve out their own spaces in international affairs. How will these changes impact the legitimacy of the United Nations? In Shared Responsibility, Carsten Staur examines the ability of the UN to combine its normative functions - defining global objectives, rules, and standards - with practical assistance for its 193 member states. Staur focuses on transformative global challenges, where the UN has the potential to play a critical role in assisting vulnerable countries in the aftermath of conflict, in further developing the concept of "responsibility to protect," in creating a more forceful system of accountability for mass atrocity crimes, and in re-launching sustainable development as the future's principal global development approach and as the basis for dealing effectively with both climate change and the responsible management of global resources. An insider's look at the UN, Shared Responsibility details the problems faced by the United Nations and presents solutions for the organization to remain relevant, legitimate, and action-oriented in the twenty-first century.