Dr. Liu is Professor at the Department of International Relations, Tsinghua University, China. He has been a visiting scholar at University of Duisburg-Essen (2006-2007), University of Groningen (2014), and University of California, San Diego (2014-2015). His current research focuses on international relations theory, international security, and international relations in East Asia. He is the author or co-editor of several books, including Alliance Politics: Theories and Practices (2018), US Military Intervention and International Order (2016), International System and Domestic Politics (2015), and The Logic of Balancing (2009) (all in Chinese). He has authored more than 80 journal articles and book chapters. His articles have appeared in various peer-reviewed journals such as International Affairs, the Chinese Journal of International Politics, and the Pacific Review.