Broms, Bengt Keywords: Aggression | Mots clefs: Agression | ABSTRACT Bengt Broms, Professor at the Faculty of Law of the University of Helsinki, devotes his course to the definition of aggression in international law. After the author’s introduction presented on the aggression in the system of the League of Nations and in bilateral and multilateral treaties, the author studies the definition of aggression in the United Nations system and in the theory of international law and the practice of the States. Bengt Broms, professeur à la Faculté de droit de l'Université d'Helsinki…