If the question of the organization of collective action, which constitutes a problem at once public and scientific, was largely studied particularly in sociology and political sciences, it remains poorly studied in transfrontier socio-urban contexts. However, operationally, the question of the organization is at the heart of the transfrontier urban planning, especially in Western Europe. A scientific research on this subject seems even more pertinent that the question of the organization is made more complex by the presence of frontiers: multiplication of actors and scales, conflict of positioning, etc. Far from disappearing, these frontiers are changing and play a crucial role in the way that the action is organized. In this perspective, this thesis explores precisely the mechanisms of cooperation between institutional actors on the one hand, and questions the role of frontiers in the production of a transfrontier metropolis on the other hand, through the case of agglomeration franco-valdo-genevoise
