Cosmopolitan conceptions of justice in global politics are gaining in importance in the field of international political theory. Cosmopolitanism claims that we owe duties of justice to all the persons of the world and thus that normative theories of global politics should focus first on the interests or welfare of persons rather than of states. Providing a thorough analysis of relevant literature and covering issues such as war and conflict, peace and human security, accountability for gross violations of human rights, environmental degradation, and the democratic deficit in transnational political actions and institutions, Patrick Hayden deftly examines the connections between accounts of cosmopolitanism and the part they play in contemporary global politics. He identifies competing theories of cosmopolitanism and defends them as strategies for serving the aims of justice in world affairs. Furthermore, he explores how cosmopolitan theories can function positively in processes of shaping international norms.