Research Faculty



Associate Professor
Department of Pan Asian Studies,
Institute for Advanced Studies on Asia

International Relations and Power Politics in East Asia

Research Topics

Ph.D. (The University of Tokyo, Graduate School of Law and Politics)

Dr. Sahashi specializes on international politics in East Asia. His recent book is In a Search for Coexistence: the United States and Two Chinas during the Cold War (Tokyo: Keiso, 2015). In English, he recently edited Looking for Leadership: The Dilemma of Political Leadership in Japan (Tokyo and New York: Japan Center for International Exchange, 2015), and wrote on the impact of rising China on Asian order, Japan’s security policy and Japan-Taiwan relations. Now he is writing his next book on US-China competition and leading two group studies on the alliance and order after the end of the Cold War.

Dr Sahashi has taught at Kanagawa University as professor until March, 2019 and has been Visiting Associate Professor, Walter H. Shorenstein Asia Pacific Research Center, Stanford University and Shigeru Yoshida Chair, Instituto Tecnológico Autónomo de México (ITAM). He joined Institute for Advanced Studies on Asia, the University of Tokyo from April, 2019.

Concurrently, he serves as Research Fellow, Japan Center for International Exchange and the member of UK-Japan 21st Century Committee. He regularly contributes to NHK, Nikkei, Asahi Shimbun, Mainichi Shimbun and other major media outlets.

He received his B.A. from International Christian University and his Ph.D. from the Graduate Schools for Law and Politics at the University of Tokyo. He also studied at Department of Political Science, University of Illinois at Urbana-Champaign. Born in 1978.

Research activities

Edited Books
  • Sahashi, Ryo Matsuda Yasuhiro, and Aoyama Waka eds.Asia Rising: A Handbook of History and International Relations in East, South and Southeast Asia The University of Tokyo Studies on Asia: Springer, 2024(in print).
  • Sahashi, R., and J. Gannon eds.Looking for Leadership: The Dilemma of Political Leadership in Japan: Japan Center for International Exchange, 2015.1.
Articles and Book Chapters
  • Teraoka, Ayumi, and Sahashi Ryo. “Japan’s Revolutionary Military Change: Explaining Why It Happened Under Kishida.”Pacific Affairs 97, no. 3 2024: 5-26.
  • Sahashi, Ryo. “Era of Cooperation and Opposition.” Asia Rising: A Handbook of History and International Relations in East, South and Southeast Asia. Edited by Yasuhiro Matsuda Ryo Sahashi, and Waka Aoyama, The University of Tokyo Studies on Asia. Berlin: Springer, 2024.
  • Sahashi, Ryo. “Japan’s strategy amid US-China confrontation.”China International Strategy Review 2, no. 2 2020.11. [Link]
  • Sahashi, R., and E. Goh. “Worldviews on the United States, Alliances, and the Changing International Order.”Contemporary Politics 2020.6.
  • Satake, T., and R. Sahashi. “Rise of China and Japan’s ‘vision’ for free and open Indo-Pacific.”Journal of Contemporary China 2020.6.
  • Sahashi, R. “The Indo-Pacific in Japan’s foreign policy.” CSIS Strategic Japan working paper: Center for Strategic and International Studies, 2019: 1-11.
  • Sahashi, R. “American Power in Japanese Security Strategy.” China’s Rise and Australia–Japan–US Relations Primacy and Leadership in East Asi. Edited by Andrew O’Neil, and Michael Heazle: Edward Elger, 2018: 143-166.
  • Sahashi, R. “Japan-Taiwan Relations since 2008: An Evolving, Practical, Non-Strategic Partnership.” Political Changes in Taiwan under Ma Ying-jeou: Partisan conflict, policy choices, external constraints and security challenges. Edited by Jean-Pierre Cabestan, and Jacques deLisle: Routledge, 2014: 232-246.
  • Sahashi, R. “Security Partnerships in Japanese Asia Strategy: Creating Order, Building Capacity, and Sharing Burden.”Asie. Visions: Institut français des relations internationales 2013.2: 1-23.
  • Sahashi, R. “The rise of China and the transformation of Asia-Pacific security architecture.” Contending Cooperation: Bilateralism, Multilateralism, and Asia-Pacific Security. Edited by William T. Tow, and Brendan Taylor: Routledge, 2013: 135-156.
  • Sahashi, R. “Security Arrangements in the Asia-Pacific: a Three-Tier Approach.” Bilateral Perspectives on Regional Security: Australia, Japan and the Asia-Pacific Regio. Edited by William T. Tow, and Rikki Kerstain: Palgrave MacMillan, 2012: 214-240.
Book Reviews
  • Sahashi, R. “The Southeast Asia Treaty Organisation. By Ang Cheng Guan. Abingdon, UK: Routledge, 2022. Hardcover: 161pp.”Contemporary Southeast Asia 44, no. 3 (2022.12): 525-527.
  • Sahashi, R. “Japanese Security Debates: Alliance, Networking, and Global Cooperation.” Presented at the International Studies Association, February 2010.
Magazine Articles
  • Ryo, Sahashi. “Deepened Division in Eurasian Politics: Enhanced San Francisco System and Strategic Resonance of Authoritarian States.”Korea On Point (2023.11): –.
  • Ryo, Sahashi. “Managing in the Middle: Japan’s strategic approach to US-China rivalry.”Global Asia 18, no. 3 (2023.9): 30-33.
  • Sahashi, R. “Japan: Making Order and Stability in Free and Open Indo Pacific.”Regional Security Outlook: CSCAP, no. 2021 (2020.12): 17-19.
  • Sahashi, R. “Indo-Pacific in Japan’s Foreign Policy.”Strategic Japan: Center for Strategic and International Studies (2019.3): 1-11.


YearAcademic experience