In its June 1954 issue, Gauche européenne celebrated the eighth year of the organisation for which it was the organ – the Mouvement socialiste des etats-unis d'Europe. A cartoon depicted a building site where iron girders formed a structure heading ever upward. Listed on each one, from bottom to top, was each successive conference of the Mouvement, from 1947 in the Paris suburb of Montrouge, 1948 in the Paris suburb of Puteaux, 1949 in Paris, before moving to Strasbourg in 1950, Frankfurt in 1952, Liege in 1953 and Milan in 1954. The journal recapped that the movement had been born between the conference at London in February 1947 (in fact a conference of the British Independent Labour Party (ILP)) and the conference in Montrouge in the same year. Prior to 1948 the organisation was named the Mouvement des etats-unis socialistes d'Europe (MEUSU). Though the movement has been given little attention in historiography of European integration, the inclusion of prominent Europeanists in its circles indicated that its importance was not negligible; to cite just a few examples: Altiero Spinelli, Paul-Henri Spaak, Andre Philip and Guy Mollet. Furthermore, in his study of early post-war socialist Europeanism, Benjamin Hecksr argues that the importance of the MSEUE's contributions to mobilisations, debate and planning warrant further examination, not only in the context of the history of socialism, but also in the historiography of the European Union.

The years 1947 to 1954 are propitious bookends to examine this movement between its origins and the burial of the plan for the European Defence Community (EDC). That proposal for a pan-European defence force was put forward by Rene Pleven in 1950, and was strongly supported by the MSEUE before it was finally sunk in the 7th arrondissement in the Assemblee nationale in August 1954. Robert Frank suggests the importance of this event in post-war European history when he writes that, ‘ce “crime du 30 aout” traumatise tous les Europeens convaincus et marque le mouvement a jamais’.

The archives of the MSEUE contain many highly detailed public policy ideas and formulations. This chapter only analyses this material to the extent that it was indicative of the movement's understanding of Europe as a whole. As a further point of clarification, the centrality of Paris to the MSEUE's discourse about Europe varied.