Diplomats often call on states to strengthen their political community, but scholars have usually failed to explain how this is done. This ambitious book looks for answers. Building on Karl Deutsch's pioneering work on "security communities," the authors investigate the notion of international community: groupings of states, tied together through common values and transnational links, that reject violent conflict resolution as unthinkable. The contributors emphasize social relations and common identity as a necessary glue. Western Europe is the most obvious case of a security community, but the authors also find hints of this phenomenon in southeast Asia and South America. The book works best when providing a framework for studying regional communities, viewing trust and shared identity as key ingredients. But even in the hands of talented scholars, the sources and workings of security communities remain elusive.