Janne, X. Keywords: Customs law | Mots clefs: Régime douanier | ABSTRACT Xavier Jeanne explains in his course that after the armistice following the Great War, the feeling of solidarity of the peoples, which emerged as a result of the calamities born out of the general conflagration, showed that certain main directives could be indicated, and that the League of Nations was an appropriate body to try to provide the economic interdependence with certain practical solutions, applicable to the Community of Stat…