Dr. Mayumi Fukushima is a Postdoctoral Fellow with the International Security Program. For the Academic Years 2022–2024, she has a U.S. Grand Strategy and U.S. Foreign Policy Postdoctoral Fellowship from the Charles Koch Foundation. 

She is currently working on three research projects on extended nuclear deterrence, asymmetric international security alliances, and nuclear nonproliferation. Her research has been published in War on the Rocks, International Affairs, The National Interest, and The American Interest, among others, and it has been supported by various organizations including the Charles Koch Foundation, the Stanton Foundation, the Smith Richardson Foundation, Massachusetts Institute of Technology’s Center for International Studies, the Murata Science Foundation, and the Ito Foundation for International Education Exchange. She was a postdoctoral Stanton Nuclear Security Fellow with the RAND Corporation in 2020-21 and a Smith Richardson Foundation predoctoral fellow at Yale University's International Security Studies Program in 2018-19. 

She earned a Ph.D. in political science from Massachusetts Institute of Technology in 2020, and was a member of MIT’s Security Studies Program. Prior to her Ph.D. training, she served as a fast-track career diplomat (deputy director) at the Japanese Ministry of Foreign Affairs for eleven years. She is fluent in English, French, and Japanese and can converse in Chinese.