The Niehaus Center for Globalization and Governance sponsored the conference The Laws of War as an International Regime: History, Theory, and Prospects, which took place October 15-17, 2015. The conference was organized by Giovanni Mantilla (CIDE), Geoffrey Wallace (Rutgers University) and Robert O. Keohane (Princeton University). Beginning with a public lecture by an official from the International Committee of the Red Cross (ICRC), the conference brought together an interdisciplinary group of scholars from political science, history, law, and philosophy to think collectively about the history, evolution, and influence of the laws of war. Papers presented included analyses of the negotiations of key conferences regulating armed conflict spread over more than a century, the commitment to specific international agreements, as well as attention to the growing role of non-state actors including rebel groups and the public. Discussion generated useful insights on the complex functioning of the laws of war and demonstrated the importance of bridging across disciplines. Participants concluded that the conference offered valuable feedback and guidance on furthering their work on the laws of war, several of whom are working on larger book-length projects on international law and the regulation of armed conflict.