Welcome! I am an Assistant Professor in the Edmund A. Walsh School of Foreign Service at Georgetown University, where I am a core faculty member of the Security Studies Program.

My first book, The Adversary’s Veto: Rival Powers, Alliance Politics, and the Limits of Grand Strategy, forthcoming in the Cornell Studies on Security Affairs series at Cornell University Press, explains why the grand strategies pursued by great powers succeed or fail in the context of military alliances. My second book, The Two-Leviathan Problem: Why Rival Hegemons Cannot Coexist (co-authored with John Mearsheimer), is forthcoming with Yale University Press and investigates the problem of “peer regional hegemons” in American grand strategy.

My scholarship speaks to a wide range of issues that arise in debates surrounding grand strategy, including preventive war, the relationship between power politics and international norms, the performative use of violence, and the making of political order. I am especially keen on developing theoretical insights using declassified primary documents and historiography on U.S. foreign policy during the Cold War, as well as the American Civil War and Reconstruction. Some of my research has been published or is forthcoming in outlets such as the American Political Science Review, International Studies Quarterly, European Journal of International Security, Texas National Security Review, Contemporary Security Policy, and Political Science Quarterly.

Policy analysis and commentary based on these works can be found in forums like The Diplomat, Foreign Affairs, Foreign Policy, and the Washington Quarterly, as well as podcasts hosted by the Cato Institute and War on the Rocks.

My research has been supported by the Smith Richardson Foundation, the Charles Koch Foundation, and the Korea Foundation for Advanced Studies, as well as the Center for East Asian Studies and the Pearson Institute for the Study and Resolution of Global Conflicts at the University of Chicago, among others.

Before beginning my academic career, I served as the personal interpreter to South Korea’s Chairman of the Joint Chiefs of Staff. In this capacity, I assisted the Chairman during all interactions with English-speaking foreign partners, including the Commander of the U.S. Forces Korea (CDRUSFK), Commander of the U.S. Pacific Command (CDRUSPACOM), and the Chairman of the U.S. Joint Chiefs of Staff (CJCS).

I received a Ph.D. in Political Science from the University of Chicago in 2022. I also hold an M.A. in Political Science from the University of Chicago and a B.A. in International Studies and Political Science, summa cum laude, from Korea University. Before joining the faculty at Georgetown, I was an Assistant Professor of Political Science at Boston College. I have also held the Stanton Nuclear Security Junior Faculty Fellowship at the Massachusetts Institute of Technology’s Center for Nuclear Security Policy, the Global Innovation Program Postdoctoral Fellowship at the University of Pennsylvania’s Perry World House, and the Hans J. Morgenthau Predoctoral Fellowship at the Notre Dame International Security Center.

Contact: joshua.byun<at>georgetown<dot>edu.