He holds a Ph.D. in International Relations from the University of Cambridge and has held fellowships at Harvard, Stanford and the Australian National University. He writes regularly on political violence, terrorism, drone warfare and American foreign policy. His previous books include Violence after War: Explaining Instability in Post-Conflict States (Baltimore: Johns Hopkins Press, 2014), Legal and Ethical Implications of Drone Warfare (London: Routledge, 2016) and Non-Western Responses to Terrorism (Manchester: Manchester University Press, 2018). He will be publishing The Drone Age: How Drone Technology Will Change War and Peace with Oxford University Press in 2018.