Dr. Sims is currently Director of Intelligence Studies and a Visiting Professor in the Security Studies Program at Georgetown University’s Walsh School of Foreign Service. She is also a consultant on intelligence and homeland security for private corporations and the US government. Prior to this, Dr. Sims served as Deputy Assistant Secretary of State for Intelligence Coordination (1994-1998) and Intelligence Advisor to the Under Secretary for Management and Coordinator for Intelligence Resources and Planning at the US Department of State (1998-2001). In the latter position, she helped coordinate the State Department budget and programs with other federal agencies involved in national security. Dr. Sims has also been a Professional Staff Member of the Senate Select Committee on Intelligence (1991-1994), and a legislative assistant to Senator John Danforth on foreign and defense policy (1990-1993). Prior to government service, Dr. Sims was the U.S. Coordinator of the multinational Nuclear History Program (1988-1990), taught as a Research Professor at Johns Hopkins University School of Advanced International Studies (2001-2003), and served as a research associate with both the L’Istituto per gli Studi di Politica Internazionale (ISPI) in Milan and the Institute for Strategic Studies (ISS) in London.

In 1998, Dr. Sims received the intelligence community's highest civilian award, the National Distinguished Service Medal.

Dr. Sims has co-edited with Burton Gerber, Transforming U.S. Intelligence (Georgetown University Press, 2005) and has published numerous articles on intelligence theory and reform. Her publications on defense technology and arms control include Icarus Restrained: an Intellectual History of Nuclear Arms Control in the United States from 1945 to 1960, (Westview Press 1985), and “The American Approach to Nuclear Arms Control: A Retrospective,” Daedalus (Winter, 1991). Current research interests include intelligence support to counter-terrorism, counter proliferation and homeland security; the application of advanced technologies to intelligence missions; Civil War intelligence; intelligence theory.