Dr. Harrison Greenleaf

Hello! I am an incoming Teaching Assistant Professor in the Curriculum in Peace, War and Defense (PWAD) at the University of North Carolina at Chapel Hill. I also hold a joint appointment with the Center for European Studies, where I teach on Contemporary European Studies. My field of study is International Relations, particularly international security, alliance politics, and populism.

I received my Ph.D. from the University of Notre Dame in 2026. I was also a pre-Doctoral Fellow with the O'Brien Notre Dame International Security Center (ONDISC) and a Graduate Student Fellow at the Nanovic Institute for European Studies. I received my undergraduate degree in International Relations and Political Theory and Constitutional Democracy from Michigan State University in 2020.

My book project, With Friends Like These, Who Needs Enemies?, explores the impact of populism on security alliances. Specifically, I examine how populist leaders manage their existing alliances and the conditions under which they either maintain or decrease their commitments. My related work on populism and NATO in U.S. public opinion has been published in Political Science Quarterly, and my work on U.S. military effectiveness is forthcoming in Security Studies.

In other research projects, I examine questions of bureaucratic politics of grand strategy, populism and institutional design, and domestic politics and war termination.