Mara Karlin

Mara Karlin is a visiting fellow at the Brookings Institution, a professor of practice at Johns Hopkins University’s School of Advanced International Studies (SAIS), and director of the Foreign Policy Institute at SAIS. Current research projects include an exploration of the changing character of war and an assessment of deterrence lessons learned and their relevance for future conflicts.

Karlin has served in national security roles for six U.S. secretaries of defense, advising on policies spanning strategic planning, defense budgeting, the future of conflict, and regional affairs involving the Middle East, Europe, and Asia. Most recently, she served as assistant secretary of defense for strategy, plans, and capabilities, leading the development and implementation of the 2022 National Defense Strategy, Nuclear Posture Review, and Missile Defense Review, the first time all major strategies were conducted simultaneously. She advised the secretary of defense on the forces, plans, posture, emerging capabilities, and security cooperation activities necessary to implement the defense strategy. She also oversaw the formation of a new emerging capabilities policy office; a historic modernization of U.S. force posture in the Indo-Pacific; the implementation of the Australia-United Kingdom-United States partnership (AUKUS); reform of the security cooperation workforce; and the development of numerous national and defense strategic guidance documents.

While serving in the Biden-Harris administration, Karlin performed the duties of deputy under secretary of defense for policy, managing the Office of the Secretary of Defense for Policy and leading a wide range of regional and functional national security, foreign policy, and defense issues. She served as acting assistant secretary of defense for international security affairs, leading the Department’s relations with nearly 150 countries in Europe (including NATO), the Middle East, Africa, Russia, Eurasia, and the Western Hemisphere. Karlin was also on the defense policy team for the Biden-Harris transition.

In the Obama-Biden administration, she served as deputy assistant secretary of defense for strategy and force development and principal director for strategy. Karlin started her government career as a civil servant in the Office of the Secretary of Defense for Policy, where she served as special assistant to the under secretary of defense for policy, Levant director, and South Asia country director.

Outside of government, Karlin was also director of strategic studies and an associate professor at SAIS, as well as a nonresident senior fellow at the Brookings Institution. She was on the 2018 National Defense Strategy Commission staff and a member of the congressionally-appointed Syria Study Group. She has written two books on military history and policy; is a recipient of the Secretary of Defense Distinguished Public Service Medal, the highest civilian award presented by the secretary of defense; and was a professor on Semester at Sea in Spring 2017 and Spring 2024.