I am a Lecturer (assistant professor) in international relations at the University of Cambridge and a fellow of Clare Hall.  My principal research interests are in international security studies, multilateralism, US foreign policy, transatlantic relations, and just war.

My latest book, Reassuring the Reluctant Warriors: US Civil-Military Relations and Multilateral Intervention, was published in 2015 with the Cornell Studies in Security Affairs book series. The book argues that America's top-ranking generals, as reluctant warriors who value international burden sharing and the potential exit ramp that a handoff to the UN or NATO can provide, play an underappreciated role in steering US intervention policy toward multilateral engagement. I have further published two books on classical international relations theory: Just and Unjust Military Intervention: European Thinkers from Vitoria to Mill (co-edited with Jennifer Welsh; Cambridge UP 2013), and A Cosmopolitanism of Nations: Giuseppe Mazzini’s Writings on Democracy, Nation Building, and International Relations (co-edited with Nadia Urbinati; Princeton UP 2009). My research has also appeared in a variety of peer-reviewed journals, including Security Studies, the Review of International Studies, Political Science Quarterly, and Ethics & International Affairs

I hold a PhD from Columbia University (awarded with distinction) and a Master's degree from the London School of Economics and Political Science. I have held fellowships at Harvard's Kennedy School of Government, the Brookings Institution, the European University Institute, and the Free University Berlin.

My name is pronounced as /stɛ́fəno /rɛ́kiə/