Interests, Institutions, and the Reliability of International Commitments


  • Earlier versions of this research were presented at the 2007 and 2008 annual meetings of the International Studies Association, Chicago and San Francisco; a 2007 PIPES workshop at the University of Chicago; the 2005 annual meeting of the Peace Science Society, Iowa City; and the 2005 annual meeting of the American Political Science Association, Washington, DC. The authors thank Jesse Johnson, Shireen Nasir, Ashwan Reddy, Patricia Restrepo, and Alice Tsao for research assistance, Zachary Elkins and Tom Ginsburg for sharing data, and Terry Chapman, Giacomo Chiozza, Joe Clare, Barbara Geddes, Hein Goemans, Marc Kilgour, Stephen Long, Lanny Martin, Cliff Morgan, Jim Morrow, Bill Reed, Burcu Savun, John Stevenson, Randy Stevenson, Mike Tomz, Greg Vonnahme, and seminar participants at PIPES and the University of Texas for helpful advice. Portions of this work were completed while Leeds was serving as a Campbell National Fellow and Susan Louise Dyer Peace Fellow at the Hoover Institution at Stanford University. Data for replication are available at

Brett Ashley Leeds is Associate Professor of Political Science, Rice University, P.O. Box 1892—MS 24, Houston, TX 77251-1892 ( Michaela Mattes is Assistant Professor of Political Science, Vanderbilt University, VU Station B #351817, Nashville, TN 37235-1817 ( Jeremy S. Vogel is a student at Columbia Law School (


One feature associated with democratic governance is frequent leadership turnover. While the ease of replacing leaders improves accountability, it may impede the ability of democracies to make credible long-term international commitments. Using newly collected data that identify cases in which leaders who derive their support from different domestic interests come to power, we evaluate the effects of changes in domestic political leadership on one important aspect of foreign policy—decisions to maintain military alliances. An analysis covering bilateral alliances between 1919 and 2001 reveals that changes in societal supporting coalitions in nondemocratic states are associated with decisions to abrogate alliances prior to their scheduled end dates, but changes in societal supporting coalitions in democracies have no effect on the probability of premature alliance termination. We conclude that international cooperation is sensitive to changes in core supporting coalitions, but that this effect is moderated by democratic political institutions.