The claim that people in developed countries have vast, unmet obligations to help people in developing countries is usually based on duties of kindness or a global extrapolation of justice among compatriots. This book constructs a different basis, the need for responsible engagement in transnational interactions in which power is currently abused. After arguing for an undemanding principle of beneficence and deriving duties of justice among compatriots from their special relations, the book develops standards of responsible conduct in current global interactions that determine: what must be done to avoid exploitation in transnational manufacturing, what framework for world trade and investment would be fair, what response to the challenge of global warming is adequate and equitable, what responsibilities to help meet basic needs arise when foreign powers steer the course of development, and what obligations are created by uses of violence to sustain global power. Through detailed empirical inquiries, the book argues that there has been a massive failure to live up to these standards, creating demanding duties to avoid undue advantage and repair abuses of power, on the part of developed countries in general and especially the United States. The book describes policies that would meet these obligations, leading obstacles, and the role of social movements in reducing injustice, especially a global form of social democracy expressing the book's perspective