Sarah Teo is an Assistant Professor in the Regional Security Architecture Programme, Institute of Defence and Strategic Studies (IDSS); Deputy Head, Graduate Studies; and, Coordinator of PhD Programme at the S. Rajaratnam School of International Studies (RSIS), Nanyang Technological University, Singapore. She was formerly Coordinator of Regional Security Architecture Programme (2021-2023) and Deputy Coordinator of MSc (International Relations) Programme (2023-2024) at RSIS. Her research interests include multilateral security cooperation in ASEAN and the Asia Pacific, middle powers in the Asia Pacific, as well as power in international relations. She is the author of Middle Powers in Asia Pacific Multilateralism: A Differential Framework (Bristol University Press, 2023), 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 work has also been published in peer-reviewed journals, edited volumes, as well as various commentary platforms. She is an editorial board member of the Australian Journal of International Affairs. She obtained her PhD from the University of Sydney.

• Multilateral security and defence cooperation in ASEAN and the Asia Pacific
• Middle powers in the Asia Pacific
• Power in international relations

• Participant, Track II Network of ASEAN Defence and Security Institutions (NADI), 2012-2015
• Member, Asia-Pacific Leadership Network for Nuclear Non-Proliferation and Disarmament (APLN), since 2023
• Editorial Board Member, Australian Journal of International Affairs, since 2024

IDSS Papers

• IP25016 | The ADMM-Plus at 15

  24 February, 2025

• IP23065 | ASEAN-ROK Relations in the Indo-Pacific: Comprehensiveness and Competitiveness

  15 September, 2023

• IP22055 | AUKUS and the Non-proliferation Debate

  13 October, 2022

• IP21002 | Creating Synergies between the ADMM and Sub-regional Arrangements

  24 August, 2021

Working Papers

• WP265 | South Korea’s Middle-Power Engagement Initiatives: Perspectives from Southeast Asia

  28 July, 2013

• WP245 | Dividing the Korean Peninsula: The Rhetoric of the George W. Bush Administration

  14 August, 2012

Policy Reports

• The Future of the ADMM/ADMM-Plus and Defence Diplomacy in the Asia Pacific

  23 February, 2016

• Impact of the Sino-Japanese Competitive Relationship on ASEAN as a Region and Institution

  24 December, 2014

• South Korea's Defence Diplomacy in East Asia

  01 December, 2013

• Strategic Engagement in the Asia Pacific: The Future of the ASEAN Defence Ministers' Meeting-Plus (ADMM-Plus)

  21 August, 2013

RSIS Commentary Series

• Reimagining DPRK Summit Diplomacy: Can ASEAN Play a Bigger Role?

  25 March, 2019

• CO17083 | Strengthening ASEAN-US Relations: Korean Peninsula as Conduit?

  02 May, 2017

• CO15234 | China-Japan-Korea Trilateral Summit: What does it mean for East Asia?

  04 November, 2015

• CO14079 | US Presence in Asia Pacific: Messages from Obama’s East Asia Tour

  30 April, 2014

• CO13078 | ASEAN Unity: From Word to Deed

  26 April, 2013

• CO13051 | Tensions on the Korean Peninsula: Will Park's Trustpolitik Work?

  02 April, 2013

• CO12226 | North Korea's Rocket Launch: Opportunity for Regional Cooperation?

  13 December, 2012

• CO12169 | ASEAN Centrality: Why it is Important for US and China

  11 September, 2012

• CO12135 | North Korea: Regime Reform or Cosmetic Change?

  26 July, 2012

• CO12115 | Japan-South Korea Military Cooperation: Implications for Northeast Asia

  04 July, 2012

Commemorative / Event Reports

• Royal Norwegian Ministry of Foreign Affairs - RSIS Asian Security Conference 2014

  13 March, 2014

Annual Reviews

• Selected Essays by RSIS Researchers - 2020

  18 January, 2021

Authored Books

• Towards Open and Inclusive Regionalism (with Rocky Intan, and Joel Ng). Indonesia, Jakarta: Centre for Strategic and International Studies, 2023
• Middle Powers in Asia Pacific Multilateralism: A Differential Framework. Bristol: Bristol University Press, 2023
• Security Strategies of Middle Powers in the Asia Pacific (with Ralf Emmers). Carlton, VIC: Melbourne University Publishing, 2018

Journal Articles

• “Recalibrating Australia’s Strategy toward Its Maritime Neighborhood” in Asia Policy, Vol. 20, No. 2, 2025, pp. 144-147
• “East Asian Regionalism” (with Sarah Soh) in Oxford Research Encyclopedia of International Studies , 2025
• “How Indonesia and Vietnam navigate coalitional networks in the Indo-Pacific” (with Ralf Emmers) in Australian Journal of International Affairs, 2025. pp. 1-19
• “Review of Multilateralism in the Indo-Pacific: Conceptual and Operational Challenges, edited by Swaran Singh and Reena Marwah (Routledge, 2022)” in Pacific Affairs, 2024
• “Review of China-US Great-Power Rivalry: The Competitive Dynamics of Order-Building in the Indo-Pacific, edited by Lai-Ha Chan and Pak K. Lee (Routledge, 2024)” in International Relations of the Asia-Pacific, 2024
• “ASEAN in the Indo-Pacific: Continuity and Change” in United Service, Vol. 74, No. 3, 2023, pp. 21-25
• “South Korea in the ASEAN-centered regional network” in Asian Politics & Policy, Vol. 15, No. 1, 2023, pp. 98-112
• “Caught in the Middle? Middle Powers Amid US-China Competition” (with Hoo Tiang Boon) in Asia Policy, Vol. 17, No. 4, 2022. pp. 59-76
• “Middle Powers amid Sino-U.S. Rivalry: Assessing the ‘Good Regional Citizenship’ of Australia and Indonesia” in The Pacific Review, Vol. 35, No. 6, 2022, pp. 1135-1161
• “Introduction on “Interests, Initiatives, and Influence: Geopolitics in the Mekong Subregion”” in Asia Policy, Vol. 17, No. 2, 2022, pp. 2-6
• “Toward a Differentiation-Based Framework for Middle Power Behavior” in International Theory, Vol. 14, No. 1, 2022, pp. 1-24
• “The Future of the San Francisco System: Pressures and Prospects” (with Ralf Emmers) in Asian Politics & Policy, Vol. 12, No. 1, 2020. pp. 84-96
• “Contending Visions of East Asian Regional Order: Insights from the United States, China, Japan, and Indonesia” (with Bhubhindar Singh, Shawn Ho, and Tsjeng Zhizhao Henrick) in Asian Affairs: An American Review, Vol. 46, No. 1, 2019. pp. 19-41
• “Can Australia be One of Us? The View from Asia” in Australian Foreign Affairs, Vol. 5, No., 2019, pp. 77-93
• Teo, Sarah. “Middle power identities of Australia and South Korea: comparing the Kevin Rudd/Julia Gillard and Lee Myung-bak administrations.” The Pacific Review 31, no. 2 (2018): 221-239.
• Bhubhindar Singh, Sarah Teo & Benjamin Ho, "Rising Sino-Japanese competition: perspectives from South-East Asian elites", Australian Journal of International Affairs, Volume 71, Issue 1, February 2017, Pages 105-120, DOI: 10.1080/10357718.2016.1157849
  
• Teo, Sarah, Bhubhindar Singh and See Seng Tan. "Southeast Asian Perspectives on South Korea’s Middle Power Engagement Initiatives." Asian Survey 56, no. 3 (2016): 555-580.
• Sarah Teo and Henrick Z Tsjeng, "A Diplomatic Decade: The ASEAN Defence Ministers' Meeting", Global Asia 11, No. 1 (Spring 2016): pp. 84-89.
• Teo, Sarah. "Dividing the Korean Peninsula: The Rhetoric of the George W. Bush Administration." The Journal of Defence and Security 6, no. 2 (2015): 1-17. 
• Desker, Barry, Sarah Teo and Dylan Loh. "The ASEAN Regional Forum and its continued relevance." New Zealand International Review 40, no. 4 (2015): 17-20.
• “Regional Security Strategies of Middle Powers in the Asia-Pacific” (with Ralf Emmers) in International Relations of the Asia-Pacific, Vol. 15, No. 2, 2014. pp. 185-216

Edited Books / Special Issues

• Minilateralism in the Indo-Pacific: The Quadrilateral Security Dialogue, Lancang-Mekong Cooperation Mechanism, and ASEAN (with Bhubhindar Singh), Eds. Oxon: Routledge, 2020

Chapters in Edited Books

• “ASEAN and the Korean Peninsula: Socialising North Korea and Beyond” in Chiew-Ping Hoo, Shine Choi and Brian Bridges (Eds.), Southeast Asia-North Korea Relations: Drivers, Linkages, and Strategic Ambivalence. Oxon: Routledge, 2025, pp. 177-190
• “ASEAN Digital Transformation and the US–China Technological Competition” (with Muhammad Faizal Bin Abdul Rahman) in Bernard F.W. Loo and James Char (Eds.), Strategic Currents: China and US Competition for Influence. Singapore: World Scientific, 2024, pp. 67-90
• “A View from Singapore: Regional Maritime Security and Cooperation with the Republic of Korea” (with Gordon Kang Yu Xuan) in Yongwook Ryu (Ed.), Republic of Korea-Singapore Security Forum: Shared Concerns, Common Goals. Singapore: Centre on Asia and Globalisation, 2024, pp. 33-37
• “Indonesia and South Korea: Middle Power Cooperation for a Resilient Indo-Pacific” (with Gabriele Abbondanza) in Sigit Aris Prasetyo (Ed.), 50 Years Indonesia and Korea: Closer Friendship, Stronger Partnership. Seoul: Ministry of Foreign Affairs of the Republic of Indonesia, 2023, pp. 131-139
• “ASEAN and Multilateralism in the Indo-Pacific: Past, Present, and Future” in Samir Saran and Vinia Mukherjee (Eds.), 2023 Raisina Files – Adrift at Sea: Lighthouse in the Tempest? . New Delhi: Observer Research Foundation, 2023, pp. 109-115
• “Singapore’s Relations with North and South Korea: In Pursuit of Pragmatism and Principles” in Lam Peng Er, Contemporary Korea-Southeast Asian Relations Bilateral and Multilateral. Oxon: Routledge, 2022, pp. 131-152
• “Advancing the ASEAN-Korea Partnership: From Sectoral Dialogue Relations to the New Southern Policy Plus” (with Ong Keng Yong, and Shawn Ho) in Kwon Hyung Lee and Yoon Jae Ro (Eds.), The New Southern Policy Plus: Progress and Way Forward. Sejong: Korea Institute for International Economic Policy, 2021, pp. 49-67
• “Middle Power Awkwardness? Indonesia’s Norm Entrepreneurship in ASEAN” in Gabriele Abbondanza and Thomas Stow Wilkins (Eds.), Awkward Powers: Escaping Traditional Great and Middle Power Theory. Cham: Palgrave Macmillan, 2021, pp. 151-176
• “Introduction: Minilateralism in the Indo-Pacific” (with Bhubhindar Singh) in Bhubhindar Singh and Sarah Teo (Eds.), Minilateralism in the Indo-Pacific: The Quadrilateral Security Dialogue, Lancang-Mekong Cooperation Mechanism, and ASEAN. Oxon: Routledge, 2020, pp. 1-12
• “The Role of Think Tanks in Shaping Policy Debates in Asia: S. Rajaratnam School of International Studies” (with Mely Caballero-Anthony, Ralf Emmers, and Theresa Robles) in James G. McGann, Think Tanks, Foreign Policy and the Emerging Powers. Cham: Palgrave Macmillan, 2018, pp. 225-237
• Cocq, Céline, and Sarah Teo. “Countering Terrorism: Challenges and Opportunities in ASEAN-EU Cooperation.” In Interregionalism and the European Union: A Post-Revisionist Approach to Europe's Place in a Changing World, edited by Mario Teló, Louise Fawcett and Frederik Ponjaert, pp. 175-191. Farnham: Ashgate, 2015.
  
  
• Henrick Z. Tsjeng, Sarah Teo and Christabelle He, with Tan Seng Chye (ed). "Singapore's experience in response to disasters at national and regional levels". In NADI Joint Working Paper: Sharing Experiences in ASEAN HADR Management, pp.64-88; recommendations pp. 111-112. Bangkok: Strategic Studies Center, National Defence Studies Institute, 2015.

Op-Eds

• “The remaking of the Indo-Pacific security architecture”, The Korea Times, 30 April 2025
• “Commentary: Singapore and South Korea ties go beyond K-pop and football” (with Ha Chae Kyoun), Channel News Asia, 10 October 2024
• “Commentary: ‘Red lines’ at Shangri-La Dialogue a reminder of need for new solutions to old problems” (with Dylan MH Loh), Channel News Asia, 5 June 2024
• “The rise and endurance of minilaterals in the Indo-Pacific”, The Interpreter, 1 May 2024
• “ASEAN Centrality: Not the Best, But Still Good?”, Counterpoint Southeast Asia , 3 October 2023
• “Commentary: It isn’t always smooth sailing, but here’s why Singapore should persist with its dialogue convenor role”, TODAY, 7 June 2023
• “The Future of the ADMM-Plus in the Indo-Pacific”, Institute for Security & Development Policy, 8 May 2023
• “A balancing act: South Korea’s Indo-Pacific turn”, Korea On Point, 20 November 2022
• “The Quad and ASEAN — Where to Next?”, East Asia Forum, 25 June 2022
• “Australia and South Korea: Resetting Middle Power Ambitions” (with Peter K. Lee), The Diplomat, 17 June 2022
• “The More Things Change… How Regional Security Multilateralism in the Asia Pacific is Evolving”, Melbourne Asia Review, 18 March 2022
• “Rules-Based Order? Strengthening Consensus on the Rules and Principles Underpinning the International Order” (with Joel Ng, and Benjamin Ho), CSCAP Regional Security Outlook 2022, 13 December 2021
• “The Ambitions and Reality of the Quad” (with Huong Le Thu), The Strategist, 15 June 2021
• “Trends in Indo-Pacific Regional Multilateralism: Scenarios for ASEAN”, ANU National Security College Futures Hub, 1 April 2021
• “Rules-Based Order? Strengthening consensus on the rules and principles underpinning the international order” (with Joel Ng, and Benjamin Ho), Asia Link Insights, 1 February 2021
• “What the Quad Meeting Means for ASEAN”, The Diplomat, 9 October 2020
• “How the COVID-19 Pandemic Deepens the Challenge of Sino-U.S Rivalry for ASEAN”, The Politburo, 10 May 2020
• “Three Scenarios for the Quad and for ASEAN” (with Amanda Trea Phua), PacNet #6, 6 February 2020
• “Strengthening the ASEAN-centric multilateral security architecture”, East Asia Forum, 7 January 2020
• “Moving ASEAN Toward Sustainable Defense Cooperation”, The Diplomat, 17 July 2019
• “South Korea steps up on the Korean Peninsula”, East Asia Forum, 12 January 2019
• “Could Minilateralism Be Multilateralism’s Best Hope in the Asia Pacific?”, The Diplomat, 15 December 2018
• Huan, Amanda, and Sarah Teo. "ASEAN 2018: Towards Resilience and Innovation in Uncertain Times." Thinking ASEAN, issue 32, February 2018. Jakarta: The Habibie Center.
• Teo, Sarah. "Debating ‘rules’, ‘order’ and ‘peace’ in the Asia-Pacific." Defense Advisers, 30 June 2017. https://www.defenseadvisers.com/general/debating-rules-order-peace-asia-pacific.
• Teo, Sarah. "Debating ‘rules’, ‘order’ and ‘peace’ in the Asia–Pacific." The Strategist, 28 June 2017. www.aspistrategist.org.au/debating-rules-order-peace-asia-pacific.
• Singh, Bhubhindar, and Sarah Teo. “ASEAN has an instrumental role in US-China power play." Channel NewsAsia, 8 May 2017. http://www.channelnewsasia.com/news/asiapacific/commentary-asean-has-an-instrumental-role-in-us-china-power-play-8826380.
• Ho, Shawn, and Sarah Teo. “After the ASEAN Summit, ASEAN should pay more attention to the North Korea threat.” Channel NewsAsia, 1 May 2017. http://www.channelnewsasia.com/news/asiapacific/commentary-after-the-asean-summit-asean-should-pay-more-8808228.
• Teo, Sarah. “The Strengths and Weaknesses of Asia’s 2 Major Defense Meetings.” The Diplomat, 21 March 2017. http://thediplomat.com/2017/03/the-strengths-and-weaknesses-of-asias-2-major-defense-meetings.
• Singh, Bhubhindar, Sarah Teo, and Benjamin Ho. "Sino-Japanese Competition and ASEAN." Australian Outlook, 9 January 2017. http://www.internationalaffairs.org.au/australian_outlook/sino-japanese-competition-and-asean.
• Teo, Sarah. "S Korea stuck between global ambitions and regional realities." Today, 11 August 2016. http://www.todayonline.com/commentary/s-korea-stuck-between-global-ambitions-and-regional-realities.
• Teo, Sarah. "South Korea stuck between global ambitions and regional realities", East Asia Forum, 9 Aug 2016.
• Teo, Sarah. Book review of North Korea-US Relations under Kim Jong Il: The Quest for Normalization? By Ramon Pacheco Pardo (Abingdon and New York: Routledge, 2014). Pacific Affairs 89, no. 1 (2016): 191-193.
• Sarah Teo, "ADMM-dialogue partners informal meetings as a source of regional stability", PacNet # 82, Pacific Forum (CSIS), 25 February 2016.
• Sarah Teo, "What does the China–Japan–South Korea Trilateral Summit mean for East Asia?", East Asia Forum, 27 November 2015.
• Teo, Sarah. “Asian Powers Hold Renewed Talks: A New Start or Same Old?” The Diplomatist, April 2015. New Delhi: L.B. Associates (Pvt) Ltd.
• Ho, Benjamin, Bhubhindar Singh, and Sarah Teo. "ASEAN Chairmanship in 2015: Perspectives and Prospects", Asia Pacific Bulletin, No. 298, 13 January 2015, http://www.eastwestcenter.org/publications/malaysia%E2%80%99s-asean-chairmanship-in-2015-perspectives-and-prospects.
• Teo, Sarah. "Seoul searching for a China–Japan diplomatic balance." East Asia Forum, December 13, 2014. http://www.eastasiaforum.org/2014/12/13/seoul-searching-for-a-china-japan-diplomatic-balance/.
• “South Korea’s Foreign Policy in 2013: Building Trust in East Asia”, E-International Relations, 6 February 2014
• Teo, Sarah. "Rocket launch offers an opportunity to cooperate." The Nation, December 19, 2012. Accessed May 25, 2014. http://www.nationmultimedia.com/opinion/Rocket-launch-offers-an-opportunity-to-cooperate-30196361.html.
• Teo, Sarah. "N. Korean rocket launch could unite neighbours." The Straits Times, December 14, 2012.
• Teo, Sarah. "North Korea: Regime reform or just Cosmetic Change?" Lianhe Zaobao, August 2, 2012.
• Teo, Sarah. "North Korea: Regime reform or just Cosmetic Change?" The Nation, July 31, 2012. Accessed May 25, 2014. http://www.nationmultimedia.com/opinion/North-Korea-Regime-reform-or-just-cosmetic-change-30187282.html.

• Guest Host, Podcast on “In Conversation: Dr Marty Natalegawa on ASEAN”, hosted by RSIS, 7 October 2024.
• Speaker, Engaging the Eagle Podcast on “Seeking Centrality – U.S.-ASEAN Ties in 2023”, hosted by United States Programme, IDSS, RSIS, 28 September 2023.
• Speaker, Panel on “The evolution of Indo-Pacific”, 36th Asia-Pacific Roundtable, organised by Institute of Strategic & International Studies (ISIS) Malaysia, 8-10 August 2023.
• Speaker, Panel on “Making and Maintaining International Order: What Asians Want”, LKYSPP Festival of Ideas, organised by Lee Kuan Yew School of Public Policy, 10 October 2022.
• Speaker, Panel on “Impact of Major Power Minilateralism on ASEAN’s Multilateralism”, 35th Asia-Pacific Roundtable, organised by Institute of Strategic & International Studies (ISIS) Malaysia, 5-7 July 2022.
• Speaker, Brookings Webinar on “South Korea’s role in the Indo-Pacific: Opportunities and challenges under the Yoon administration”, organised by The Brookings Institution, 18 May 2022.
• Speaker, Virtual Panel Discussion on “Re-imagining multilateralism and rules-based order”, ANU Crawford Leadership Forum, organised by Australian National University, 6-7 September 2021
• Speaker, Virtual Panel Discussion on “The Australia-US Alliance: Views from the Region”, organised by the United States Studies Center, 20 August 2021
• Speaker, The Katipunan Dialogue Podcast on “Regional Crisis Management: Multilateralism”, hosted by Strategic Studies Program, Center for Integrative and Development Studies, University of the Philippines, 23 July 2021
• Speaker, Podcast on “The grey zone, hybrid war, and minilateralism”, by ANU National Security College Futures Hub, 17 June 2021

• IR6001 – The Study of International Relations
• IR6042 – ASEAN and the Security Architecture in Asia