Theorizing international responsibility law, an introduction Samantha Besson; Part I. International Responsibility of Public Institutions: Public and/or Private?: 1. From 'respondere' to 'responsibility': A Roman lawyer's gloss on the international law of state responsibility Dario Mantovani; 2. Change in the law of international responsibility André Nollkaemper; 3. State responsibility: an outsider's view R. A. Duff; 4. Responsibility of states for wrongdoing: who is to decide? Alon Harel and Julian Kulaga; Part II. International Responsibility of Public Institutions: Collective and/or Individual?: 5. Responsibility as opportunism: the responsibility of international organizations Jan Klabbers; 6. Responsibility of members of an international organization: collective and/or individual? Paolo Palchetti; 7. International responsibility for global environmental harm: collective and individual Liam Murphy; 8. Justifying liability for state remedial duties Sandy Steel; Part III. International Responsibility of Public Institutions: Fault-Based or Not?; 9. Responsibility or liability: is it really that simple? Pierre d'Argent; 10. Causation, fault, and function in the rules of attribution Sean Fleming; 11. Time travel in the law of international responsibility Jean d'Aspremont; Part IV. Responsibility of Public Institutions: A World Tour: 12. The responsibility of public authorities in China Frédéric Constant; 13. Liability of public institutions in Middle Eastern law Chibli Mallat; 14. The responsibility of public institutions in Africa: a legal framework in the making Ousmane Oumarou Sidibé; 15. State responsibility from a Central European perspective Krzysztof Wojtyczek; 16. Comparative and prospective comments on the 'world tour' of the concept of public responsibility Mireille Delmas-Marty; Conclusion: responsibility at the crossroad between philosophy and law Pierre-Marie Dupuy.