Thomas Donnelly, a defense and security policy analyst, is the co-director of the Marilyn Ware Center for Security Studies at AEI.

He is the co-author with Frederick W. Kagan of Lessons for a Long War: How America Can Win on New Battlefields (2010). Among his recent books are Ground Truth: The Future of U.S. Land Power (2008), co-authored with Frederick W. Kagan; Of Men and Materiel: The Crisis in Military Resources (2007), co-edited with Gary J. Schmitt; The Military We Need (2005); and Operation Iraqi Freedom: A Strategic Assessment (2004).

From 1995 to 1999, he was policy group director and a professional staff member for the House Committee on Armed Services. Mr. Donnelly also served as a member of the U.S.-China Economic and Security Review Commission. He is a former editor of Armed Forces Journal, Army Times, and Defense News.