J. David Singer's legendary Correlates of War project represented the first comprehensive effort by political scientists to gather and analyze empirical data about the causes of war. In doing so, Singer and his colleagues transformed the face of twentieth-century political science. Their work provoked some of the most important debates in modern international relations -- about the rules governing territory, international intervention, and the so-called "democratic peace."Editor Paul F. Diehl has now convened some of the world's foremost international conflict analysis specialists to reassess COW's contribution to our understanding of global conflict. Each chapter takes one of COW's pathbreaking ideas and reevaluates it in light of subsequent world events and developments in the field. The result is a critical retrospective that will reintroduce Singer's important and still-provocative findings to a new generation of students and specialists.Paul F. Diehl is Professor of Political Science and University Distinguished Scholar at the University of Illinois, Urbana-Champaign.