The late Colin S. Gray was Professor of International Politics and Strategic Studies at the University of Reading, UK, and a professional strategic theorist and defence analyst. His 30 books include Modern Strategy (1999), Another Bloody Century (2005) and The Strategy Bridge (2010).

James J. Wirtz is Professor of National Security Affairs at the Naval Postgraduate School, Monterey, California, USA. He is co-editor of Strategy in the Contemporary World 7th edition (2022) and author of Understanding Intelligence Failure: Warning, Response and Deterrence (2017).