Sarah Teo is an Assistant Professor in the Regional Security Architecture Programme and Deputy Coordinator of the MSc (International Relations) Programme at the S. Rajaratnam School of International Studies (RSIS), Nanyang Technological University, Singapore. Her research interests include multilateral security and defence cooperation in ASEAN and the Asia Pacific, middle powers in the Asia Pacific, as well as power in international relations. Her latest book is Middle Powers in Asia Pacific Multilateralism: A Differential Framework (Bristol University Press, 2023). She is the co-author of Security Strategies of Middle Powers in the Asia Pacific (Melbourne University Publishing, 2018) and co-editor of Minilateralism in the Indo-Pacific: The Quadrilateral Security Dialogue, Lancang-Mekong Cooperation Mechanism, and ASEAN (Routledge, 2020). Her articles have also been published in peer-reviewed journals such as International Theory, The Pacific Review and Asia Policy, edited volumes, as well as various commentary platforms. She has a PhD from the University of Sydney and MSc (International Relations) from RSIS.