The "World Social Science Advanced Lecture" (No. 80), organized by the Fudan Institute for Advanced Study in Social Sciences (Fudan IAS) and Contemporary China Research Center at Fudan University, was held on May 27, 2025, at Fudan University. Jean-Marc Coicaud, chair professor at Fudan University, internationally renowned jurist and political scientist, member to the European Academy of Arts and Sciences, and Distinguished Professor at Rutgers University, gave a lecture entitled The Law and Politics of International Legitimacy: Can International Law and International Order Be Legitimate?. Prof. Sujian Guo, Dean and Distinguished Professor of Fudan IAS chaired this event.

In the opening speech, Prof. Sujian Guo expressed his warm welcome to Prof. Coicaud, and introduced Prof. Coicaud's research fields and major publications. Prof. Coicaud has long been engaged in the study of political legitimacy, global justice, international law and related fields. He has published 17 books and more than 100 academic papers. His new book, The Law and Politics of International Legitimacy, will be published by Cambridge University Press in spring 2025. Prof. Coicaud thanked Prof. Guo for his introduction, and then started his lecture.

Prof. Coicaud began by sharing the origins of his research on the legal and political aspects of international legitimacy. He stated three challenges of legitimacy in and of international law. Firstly, at the United Nations in the 1990s, he observed tensions between principles of international legitimacy such as sovereignty and human rights. Secondly, in Asia in the 2000s (Japan and beyond), he observed non-Western countries (the Global South) questioning the legitimacy of international law. Thirdly, more recent challenge to the legitimacy in and of international law, the Trump administration's rejection of the principles of international law. These three challenges show that in the context of international law and order, international legitimacy is a key factor in promoting international security based on considerations of justice, and that legitimacy is of great significance at the international level.

Prof. Coicaud then talked about his new book The Law and Politics of International Legitimacy. This book addressed five main questions, which are 1) What is legitimacy in general? 2) What is legitimacy at the international level? 3) How does international law build a sense of legitimacy? 4) What are the limits of legitimacy in and of international law? 5) How to improve the legitimacy of international law and international order? Based on these questions, Prof. Coicaud further introduced the main content of this book.

In the final part of the lecture, Prof. Coicaud proposed six principles for strengthening the legitimacy of international law and the international system: consent, justification, accountability, consistency, participation and representation, and non-abuse of power. Looking ahead, Prof. Coicaud believed that cooperation remains indispensable and that the logic of right rather than might will lead to more robust national and international security.

After Prof. Coicaud’s sharing, Prof. Sujian Guo chaired a Q&A session. Prof. Coicaud responded the questions raised by the participants one by one, and continued to have an in-depth discussion on the legitimacy of international law. At the end of the event, Prof. Guo congratulated Prof. Coicaud on the publication of his new book, and expressed his gratitude to him for the rich and wonderful sharing. The lecture was successfully concluded with warm applause.