Holmes has published or has articles forthcoming in International Organization, International Studies Perspectives, Review of Policy Research, International Relations of the Asia-Pacific, Journal of Transportation Security, and Homeland Security Affairs. He is currently working on a book manuscript and projects involving experimental methods, social neuroscience, and the role of personal diplomacy in international crises. He teaches international relations, international political economy, foreign policy, diplomacy, homeland security affairs, and terrorism. He earned his doctorate from The Ohio State University and has previously taught at Georgetown University and The Ohio State University.