International Law, Norms, and the Decline in Interstate War

This event focuses on a discussion paper, “International Law, Norms, and the Decline in Interstate War,” by Kathryn Sikkink and Averell Schmidt. The authors will not present the paper formally, and participants are expected to read the paper in advance. Please e-mail pacs@cornell.edu for the paper.

The authors argue that international laws governing the initiation of war – jus ad bellum – reduce the likelihood of interstate war under two conditions: when treaties are interpreted as prohibiting interstate war and when the application of treaties is not counteracted by other international norms. The development of international law in the interwar period shows that the letter of treaties is not always closely related to states’ interpretation of their normative commitments. This disjuncture is key to understanding the impact of international law on interstate war initiation.

Sikkink and Schmidt demonstrate statistically that ratification of treaties understood to reflect the norm prohibiting interstate war is associated with a decrease in states’ propensity to initiate wars deemed unlawful by treaties and illegitimate by international norms. Indeed, only three of the 64 illegal and illegitimate wars occurring between 1929 and 2010 were initiated by belligerents that had each ratified more than one anti-war treaty. They couple this statistical analysis with case studies from Latin America, demonstrating the role of laws and norms in shaping the decision to go to war.

About the Authors
Kathryn Sikkink is the Ryan Family Professor of Human Rights Policy at the Harvard Kennedy School. She works on international norms and institutions, transnational advocacy networks, the impact of human rights law and policies, transitional justice, and the laws of war.

Her publications
International, Norms, Moral Psychology, and Neuroscience (with Richard Price); The Hidden Face of Rights: Toward a Politics of Responsibilies; Evidence for Hope: Making Human Rights Work in the 21st Century; The Justice Cascade: How Human Rights Prosecutions are Changing World Politics (awarded the Robert F. Kennedy Center Book Award and the WOLA/Duke University Award); Mixed Signals: U.S. Human Rights Policy and Latin America; Activists Beyond Borders: Advocacy Networks in International Politics (co-authored with Margaret Keck and awarded the Grawemeyer Award for Ideas for Improving World Order and the ISA Chadwick Alger Award for Best Book in the area of International Organizations); and The Persistent Power of Human Rights: From Commitment to Compliance (co-edited with Thomas Risse and Stephen Ropp). 

Averell Schmidt is a Postdoctoral Research Associate in International and Public Affairs at Brown University’s Watson Institute for International and Public Affairs. He received his Ph.D. in Public Policy from Harvard University in May 2024. He was previously a Transitional Justice Fellow at the Carr Center for Human Rights Policy, a Research Fellow in the International Security Program at the Belfer Center for Science and International Affairs, and a Hans J. Morgenthau Fellow at the Notre Dame International Security Center. 

Host
Reppy Institute for Peace and Conflict Studies