A. Gross, Ernest Keywords: United Nations | Charter | Collective security | Mots clefs: Nations Unies | Charte | Sécurité collective | ABSTRACT Ernest Gross emphasizes in the introduction of his course that observers and practitioners wonder about where the great unpopularity of international collaboration institutions comes from or how often they are ignored, even though they have a certain link with human well-being and progress. The author proposes in this course to present the causes of these inconsistencies. Afte…