Jakub Grygiel is anassociate professorat the CatholicUniversity of America (Washington, D.C.). In 2017-2018 he was a senior advisor in the Office of Policy Planning at the U.S. Department of State. Previously, he was a Senior Fellow at the Center for European Policy Analysis and on the faculty of SAIS-Johns Hopkins University in Washington, D.C. He is the author of Return of the Barbarians (Cambridge University Press, 2018), Great Powers and Geopolitical Change (JHU Press, 2006), and co-author with Wess Mitchell of The Unquiet Frontier (Princeton University Press, 2016). His writings on international relations and security studies have appeared in Foreign Affairs, The American Interest, Security Studies, Journal of Strategic Studies, Orbis, The National Interest, Commentary, Parameters, as well as several U.S. and foreign newspapers. He earned a Ph.D., M.A., and an MPA from Princeton University, and a BSFS Summa Cum Laude from Georgetown University.