The Vienna Conventions on the Law of Treaties

Olivier Corten is a Professor at the Université libre de Bruxelles and Director of the Centre de Droit International. He has taught at various universities in Belgium, Germany, Spain, Portugal, France, Italy, Brazil and Japan, as well as at the UN and The Hague Academy of International Law. He has authored or co-authored 15 books and over 170 articles published in various international law journals. Since 2002, he has been Director, then Co-Director, of the Belgian Review of International Law. In 2019, he was elected Associate Member of the Institut de Droit International, becoming a full Member in 2023. As a lawyer, he has appeared before the International Court of Justice in several cases.Pierre Klein teaches public international law and is Dean of the Faculty of Law and Criminology at the Université libre de Bruxelles. He taught as a Visiting Lecturer or Professor at the Université catholique de Louvain, the University of Ottawa, McGill University, the University of Abomey-Calavi (Bénin), the University of Paris XI, and the Hague Academy of International Law. He is the author or co-author of four books including Bowett's Law of International Institutions (5th ed., Sweet and Maxwell) and more than 70 articles, notes, and chapters published in various international law journals and books. He is also active as a consultant to various States and international organizations, and has acted as counsel in numerous cases before the International Court of Justice and the International Tribunal for the Law of the Sea.Vaios Koutroulis is a Professor at the Université libre de Bruxelles. He has given numerous lectures both in Belgium and abroad, including lectures on international humanitarian law and international criminal law for members of the armed forces, humanitarians, and other professionals. Since 2022, he has been a Member of the International Humanitarian Fact-Finding Commission. He is a General Editor of The Military Law and the Law of War Review and a member of the editorial board of the Belgian Review of International Law. As a practitioner, he was a member of the legal team of Belgium before the International Court of Justice in 2012 and 2024. He has advised the Belgian Ministry of Foreign Affairs on international criminal law questions relating to the Ljubljana-The Hague Convention and chaired one of the three working groups at the negotiations of the convention.Anne Lagerwall is a Professor at the Université libre de Bruxelles. She has given lectures in universities in Belgium, France, The Netherlands, and Italy as well as for the UN International Law Fellowship Programme in The Hague and Addis Ababa. She was the Director of Research for the Hague Academy of International law in 2024 (French-speaking section). She has also served as the Director of the International Law Center at the Université libre de Bruxelles and as the Vice-President of the Belgian Society of International Law. Since 2012, she has been the co-Director of the Belgian Review of International Law and since 2024 she has been a member of the scientific committee of the European Journal of International Law.

A major strength of the work lies in its systematic examination of each provision's object and purpose, closely reflecting the interpretative approach of international courts and tribunals. Equally valuable is its consistent analysis of the customary status of each article. This allows practitioners to determine applicable rules when dealing with non-parties to the VCLT and mixed treaty regimes, such as those involving the EU.

• 1: Paolo Palchetti: Preamble to the Convention of 1969 2: Eric David: Preamble to the Convention of 1986 Part I: Introduction 3: Philippe Gautier: Article 1 1969 4: Philippe Gautier: Article 1 1986 5: Philippe Gautier: Article 2 1969 6: Philippe Gautier: Article 2 1986 7: Yves le Bouthillier and Jean-François Bonin: Article 3 1969 8: Yves le Bouthillier and Jean-François Bonin: Article 3 1986 9: Frédéric Dopagne: Article 4 1969 10: Frédéric Dopagne: Article 4 1986 11: David Heywood Anderson and Michael Wood: Article 5 1969 12: David Heywood Anderson and Michael Wood: Article 5 1986 Part II: Conclusion and Entry into Force of Treaties 13: Daniel Turp, François Roch, and Blaise-Pascal Ntirumenyerwa Mihigo: Article 6 1969 14: Nicolas Levrat: Article 6 1986 15: Peter Kovacs: Article 7 1969 16: Peter Kovacs: Article 7 1986 17: Nicolas Angelet, Tamara Leidgens, and Marta Duch Giménez: Article 8 1969 18: Nicolas Angelet: Article 8 1986 19: Maurice Kamto and Ana Peyro Llopis: Article 9 1969 20: Maurice Kamto: Article 9 1986 21: Jean-Marc Thouvenin and Victor Grandaubert: Article 10 1969 22: Jean-Marc Thouvenin and Victor Grandaubert: Article 10 1986 23: Florence Poirat: Article 11 1969 24: Sandra Szurek and Florence Poirat: Article 11 1986 25: Cédric van Assche: Article 12 1969 26: Cédric van Assche: Article 12 1986 27: Cédric van Assche: Article 13 1969 28: Cédric van Assche: Article 13 1986 29: Rafâa Ben Achour, Imed Frikha, and Mounir Snoussi: Article 14 1969 30: Rafâa Ben Achour, Imed Frikha, and Mounir Snoussi: Article 14 1986 31: Jean-François Marchi and Niki Aloupi: Article 15 1969 32: Jean-François Marchi and Niki Aloupi: Article 15 1986 33: Ferhat Horchani and Youssri Ben Hammadi: Article 16 1969 34: Ferhat Horchani and Youssri Ben Hammadi: Article 16 1986 35: Carol Hilling and Anne-Thida Norodom: Article 17 1969 36: Carol Hilling: Article 17 1986 37: Laurence Boisson de Chazournes and Makane Moïse Mbengue: Article 18 1969 38: Laurence Boisson de Chazournes and Makane Moïse Mbengue: Article 18 1986 39: Daniel Müller: Article 19 1969 40: Daniel Müller: Article 19 1986 41: Daniel Müller: Article 20 1969 42: Daniel Müller: Article 20 1986 43: Daniel Müller: Article 21 1969 44: Daniel Müller: Article 21 1986 45: Daniel Müller: Article 22 1969 46: Daniel Müller: Article 22 1986 47: Alain Pellet and William Schabas: Article 23 1969 48: Alain Pellet and William Schabas: Article 23 1986 49: Ivon Mingashang: Article 24 1969 50: Ivon Mingashang: Article 24 1986 51: Denise Mathy and Juan Manuel Gómez Robledo: Article 25 1969 52: Denise Mathy and Juan Manuel Gómez Robledo: Article 25 1986 Part III: Observance, Application, and Interpretation of Treaties 53: Jean Salmon and Agatha Verdebout: Article 26 1969 54: Jean Salmon and Agatha Verdebout: Article 26 1986 55: Christina Binder and Annemie Schaus: Article 27 1969 56: Christina Binder and Maxime Didat: Article 27 1986 57: Frédéric Dopagne: Article 28 1969 58: Frédéric Dopagne: Article 28 1986 59: Syméon Karagiannis: Article 29 1969 60: Syméon Karagiannis: Article 29 1986 61: Alexander Orakhelashvili: Article 30 1969 62: Alexander Orakhelashvili: Article 30 1986 63: Jean-Marc Sorel and Valérie Boré Eveno: Article 31 1969 64: Jean-Marc Sorel and Valérie Boré Eveno: Article 31 1986 65: Yves le Bouthillier: Article 32 1969 66: Yves le Bouthillier: Article 32 1986 67: Alain Papaux and Rémi Samson: Article 33 1969 68: Alain Papaux and Rémi Samson: Article 33 1986 69: Eric David: Article 34 1969 70: Emmanuel Klimis and Charlotte Dahin: Article 34 1986 71: Caroline Laly-Chevalier and Danae Azaria: Article 35 1969 72: Caroline Laly-Chevalier and Danae Azaria: Article 35 1986 73: Pierre d'Argent: Article 36 1969 74: Pierre d'Argent: Article 36 1986 75: Pierre d'Argent: Article 37 1969 76: Pierre d'Argent: Article 37 1986 77: Giorgio Gaja: Article 38 1969 78: Giorgio Gaja: Article 38 1986 Part IV: Amendment and Modification of Treaties 79: Vaios Koutroulis: Article 39 1969 80: Vaios Koutroulis: Article 39 1986 81: Karine Ardault and Daniel Dormoy: Article 40 1969 82: Karine Ardault and Daniel Dormoy: Article 40 1986 83: Anne Rigaux, Denys Simon, Joanna Spanoudis, Edith Weemaels, and Patrícia Galvão Teles: Article 41 1969 84: Joanna Spanoudis, Edith Weemaels, and Patrícia Galvão Teles: Article 41 1986 Part V: Invalidity, Termination, and Suspension of the Operation of Treaties 85: Marcelo G. Kohen and Lorenzo Palestini: Article 42 1969 86: Marcelo G. Kohen and Lorenzo Palestini: Article 42 1986 87: Karine Bannelier: Article 43 1969 88: Karine Bannelier: Article 43 1986 89: Martyna Falkowska, Mohammed Bedjaoui, Tamara Leidgens, and Odile Dua: Article 44 1969 90: Mohammed Bedjaoui, Maxime Didat, and Tamara Leidgens: Article 44 1986 91: Marcelo G. Kohen and Lorenzo Palestini: Article 45 1969 92: Marcelo G. Kohen and Lorenzo Palestini: Article 45 1986 93: Michael Bothe: Article 46 1969 94: Michael Bothe: Article 46 1986 95: Florian Hoffmann and Hannah De Gregorio Leão: Article 47 1969 96: Florian Hoffmann and Hannah De Gregorio Leão: Article 47 1986 97: Éric Wyler and Rémi Samson: Article 48 1969 98: Éric Wyler and Rémi Samson: Article 48 1986 99: Gérard Niyungeko: Article 49 1969 100: Gérard Niyungeko: Article 49 1986 101: Jean-Pierre Cot and Alexandra Hofer: Article 50 1969 102: Jean-Pierre Cot and Alexandra Hofer: Article 50 1986 103: Giovanni Distefano: Article 51 1969 104: Giovanni Distefano: Article 51 1986 105: Olivier Corten and Mathias Forteau: Article 52 1969 106: Olivier Corten and Mathias Forteau: Article 52 1986 107: Dire Tladi and Eric Suy: Article 53 1969 108: Anne Lagerwall: Article 53 1986 109: Vincent Chapaux, Malgosia Fitzmaurice, and Agnes Rydberg: Article 54 1969 110: Vincent Chapaux, Malgosia Fitzmaurice, and Agnes Rydberg: Article 54 1986 111: Vincent Chapaux and Mamadou Hébié: Article 55 1969 112: Vincent Chapaux and Mamadou Hébié: Article 55 1986 113: Theodore Christakis and Panos Merkouris: Article 56 1969 114: Theodore Christakis and Panos Merkouris: Article 56 1986 115: Rosario Huesa Vinaixa: Article 57 1969 116: Rosario Huesa Vinaixa: Article 57 1986 117: Marie-Pierre Lanfranchi, Olufemi Elias, and Chloé Faucourt: Article 58 1969 118: Marie-Pierre Lanfranchi: Article 58 1986 119: François Dubuisson: Article 59 1969 120: François Dubuisson: Article 59 1986 121: Bruno Simma and Christian J. Tams: Article 60 1969 122: Bruno Simma and Christian J. Tams: Article 60 1986 123: Pierre Bodeau-Livinec and Jason Morgan-Foster: Article 61 1969 124: Pierre Bodeau-Livinec and Jason Morgan-Foster: Article 61 1986 125: Malcolm N. Shaw and Caroline Fournet: Article 62 1969 126: Malcolm N. Shaw and Caroline Fournet: Article 62 1986 127: Nicolas Angelet and Marta Duch Giménez: Article 63 1969 128: Corinne Clavé and Eugénie Delval: Article 63 1986 129: Anne Lagerwall: Article 64 1969 130: Anne Lagerwall: Article 64 1986 131: Mario Prost: Article 65 1969 132: Mario Prost: Article 65 1986 133: Hélène Ruiz Fabri: Article 66 1969 134: Hélène Ruiz Fabri: Article 66 1986 135: Antonios Tzanakopoulos: Article 67 1969 136: Didier Rouget and Antonios Tzanakopoulos: Article 67 1986 137: Antonios Tzanakopoulos: Article 68 1969 138: Didier Rouget and Antonios Tzanakopoulos: Article 68 1986 139: Paulina Starski: Article 69 1969 140: Paulina Starski: Article 69 1986 141: Hervé Ascensio: Article 70 1969 142: Hervé Ascensio: Article 70 1986 143: François Crépeau, René Côté, Sean Rehaag, François Roch, and Blaise Pascal Ntirumenyerwa Mihigo: Article 71 1969 144: François Crépeau, René Côté, Sean Rehaag, François Roch, and Blaise Pascal Ntirumenyerwa Mihigo: Article 71 1986 145: Philippe Couvreur and Carlos Espaliú Berdud: Article 72 1969 146: Philippe Couvreur and Carlos Espaliú Berdud: Article 72 1986 Part VI: Miscellaneous Provisions 147: René Provost: Article 73 1969 148: Robert Kolb: Article 73 1986 149: David Heywood Anderson and Michael Wood: Article 74 1986 150: Nicolas Angelet, Corinne Clavé, and Marta Duch Giménez: Article 74 1969 151: Nicolas Angelet and Corinne Clavé: Article 75 1986 152: Christian Tomuschat: Article 75 1969 153: Christian Tomuschat: Article 76 1986 Part VII: Depositaries, Notifications, Corrections, and Registration 154: Lucius Caflisch: Article 76 1969 155: Lucius Caflisch: Article 77 1986 156: Fatsah Ouguergouz, Santiago Villalpando, and Jason Morgan-Foster: Article 77 1969 157: Fatsah Ouguergouz, Santiago Villalpando, and Jason Morgan-Foster: Article 78 1986 158: Riad Daoudi: Article 78 1969 159: Riad Daoudi: Article 79 1986 160: Robert Kolb: Article 79 1969 161: Robert Kolb: Article 80 1986 162: Pierre Klein: Article 80 1969 163: Pierre Klein: Article 81 1986 Part VIII: Final Provisions 164: Nicolas Burniat and Marie-Laurence Hébert-Dolbec: Article 81 1969 165: Nicolas Burniat and Marie-Laurence Hébert-Dolbec: Article 82 1986 166: Nicolas Burniat and Marie-Laurence Hébert-Dolbec: Article 82 1969 167: Nicolas Burniat and Marie-Laurence Hébert-Dolbec: Article 83 1986 168: Nicolas Burniat and Marie-Laurence Hébert-Dolbec: Article 83 1969 169: Nicolas Burniat and Marie-Laurence Hébert-Dolbec: Article 84 1986 170: Catherine Denis: Article 84 1969 171: Catherine Denis: Article 85 1986 172: Catherine Denis: Article 85 1969 173: Catherine Denis: Article 86 1986 174: Mariano J. Aznar-Gómez and Zeynep Pirim: Annex to the Convention of 1969 175: Mariano J. Aznar-Gómez and Zeynep Pirim: Annex to the Convention of 1986 176: Frédéric Mégret: Declaration on the Prohibition of Military, Political, or Economic Coercion in the Conclusion of Treaties