Mara Karlin, PhD, is associate professor of practice and associate director of strategic studies at Johns Hopkins-SAIS. Karlin has served in national security roles for five U.S. Secretaries of Defense, advising on policies spanning strategic planning, defense budgeting, future wars and the evolving security environment, and regional affairs involving the Middle East, Europe, and Asia. Most recently, she served as the deputy assistant secretary of defense for strategy & force development. In that role, her office crafted strategies for navigating the future of international security—including through the analysis of future wars— as a means to guiding the development of a prepared, capable, and effective U.S. military. She oversaw and implemented the overarching policy and strategy guidance that shapes the Department’s more than $550 billion budget, and was a key architect of the 2014 QDR; the 2015 NSS; and the 2014, 2015, and 2016 Defense Planning Guidance, among others. Her first book, Building Militaries in Fragile States: Challenges for the United States, will be published by University of Pennsylvania Press in 2017.