The post World War II fabric of global security, designed and maintained by the United States, has dangerously frayed. Built for a different age, current international institutions are ill equipped to address today's most pressing global security challenges, ranging from climate change and nuclear proliferation to civil strife and terrorism. Revitalizing the institutions of cooperation will require a new conceptual foundation for global security. The 'national sovereignty' of the twentieth century must give way to 'responsible sovereignty' a principle requiring nations not only to protect their own people, but also to cooperate across borders to safeguard common resources and tackle common threats. Achieving this will require American leadership and commitment to a rule based international order.In 'Power and Responsibility' Bruce Jones, Carlos Pascual, and Stephen Stedman provide the conceptual underpinnings for a new approach to sovereignty and cooperation. They present ideas for the new U.S. administration, working with other global powers, to promote together what they cannot produce apart peace and stability. Recommendations follow more than a year of consultations with policymakers and experts all over the world. They reflect the guidance of the Managing Global Insecurity Project Advisory Group, composed of prominent figures from the United States and abroad. They call for the new president and key partners to launch a 2009 campaign to revitalize international cooperation and rejuvenate international institutions. As Washington prepares for a presidential transition, the time has arrived for a serious rethinking of American policy. For the United States, this is no time to go it alone.