Mastro’s area of research focuses on military operations and strategy, war termination, and Northeast Asia. She examines in particular Chinese strategic thinking and military modernization. She has worked on U.S.-China security and defense issues at U.S. Pacific Command and U.S. Department of Defense as well as at the Carnegie Endowment for International Peace, Center for Strategic and International Studies, RAND Corporation, Project 2049 Institute and the Center for a New American Security (CNAS). She is also a captain in the United States Air Force Reserve where she works at the Pentagon as an Asia-Pacific strategist. She is also a member of National Committee on United States-China Relations and CSIS Pacific Forum Young Leaders Program.