Au lendemain de la Premire Guerre mondiale, la diplomatie est rinventer. Un nouvel ordre international merge au sein duquel juristes internationaux, journalistes, banquiers d’affaires et autres experts concurrencent dsormais les diplomates de mtier. De nouvelles arnes diplomatiques apparaissent, l’instar de la Socit des Nations, anctre des organisations multilatrales actuelles. travers les dix tudes de cas prsentes ici, le continent europen apparat comme un terrain propice l’invention de pratiques diplomatiques nouvelles tout au long du XXe sicle. Cet ouvrage collectif constitue les actes du colloque international de l’association RICHIE sur les sociabililits, rseaux et pratiques diplomatiques en Europe de 1919 nos jours tenues Bruxelles, les 20 et 21 mars 2015. After the First World War, reshaping the art of diplomacy is a necessity. International lawyers, merchant bankers, academics, journalists and senior officials became key-figures of a new International order in which the diplomats have lost their monopoly over foreign affairs. New diplomatic arenas emerged such as the League of Nations, the precursor of today’s multilateral organizations. In that series of ten case studies, the European continent appears as a fertile ground where new diplomatic practices have emerged along the whole 20th century. This book brings together the edited proceedings of the RICHIE International Conference organized in Brussels on 20 and 21 March 2015, under the title Networks, Dynamics of Socialization and Practices in European Diplomacy since 1919.