Elbridge Colby

Elbridge Colby

Formal First Name

Elbridge Colby is the Co-founder and Principal of The Marathon Initiative, a nonprofit research organization that aims to develop the diplomatic, military, and economic strategies of the nation. Prior to launching The Marathon Initiative, he served as the Director of the Defense Program at the Center for a New American Security, where he led the Center's work on defense issues. He has also served as US Deputy Assistant Secretary of Defense for Strategy and Force Development and was the chief architect of the 2018 National Defense Strategy (NDS), which was by some estimates the most significant revision of U.S. defense strategy since 9/11, if not since the end of the Cold War. Previously, Colby was the Robert M. Gates Fellow at the Center for a New American Security (CNAS), where he focuses on strategic, deterrence, nuclear weapons, conventional force, intelligence, and related issues. Earlier in his career he served for over five years in the U.S. Government working on a range of strategic forces, arms control, WMD, and intelligence reform matters. Colby is the author of The Strategy of Denial: American Defense in an Age of Great Power Conflict, which The Wall Street Journal selected as one of the top ten books of 2021.

Professional Experience

Academic History


  • He was responsible for developing the Defense Planning Guidance and the Defense Planning Scenarios.

  • He served as a lead Policy representative to the Program and Budget Review and Support for Strategic Analysis processes. 

  • He was a consultant for the 2014 National Defense Panel, the 2008-2009 Strategic Posture Commission, and the 2004-2005 President’s WMD Commission. 


  • He has served as a consultant to a variety of U.S. government entities on a range of defense and intelligence matters.

  • He has also been an adjunct staff member with the RAND Corporation and has served as a consultant to a number of U.S. Government bodies.


  • Exceptional Public Service Award, Office of the Secretary of Defense

  • Superior Meritorious Honor Awards, Department of State


  • Colby is a frequent commentator and author on defense and foreign policy issues.

  • He speaks frequently to government, expert, university, and broader public audiences in the US, Europe, and Asia.

  • His work has appeared in outlets such as The Wall Street Journal, Foreign Affairs, The Washington Post, The New York Times, Foreign Policy, and The National Interest.

  • His work also appeared in Asahi Shimbun, Yomiuri Shimbun, Nikkei Asia, The Hindustan Times, The Australian, Süddeutsche Zeitung, Frankfurter Allgemeine Zeitung, Internationale Politik, Die Zeit, Le Figaro, The Spectator, Survival, La Stampa, The Taipei Times, Hankook Ilbo, The New Straits Times, and The Manila Standard.