In this chapter, we propose to tackle the question of the rescaling of political action through the implementation of public policies and, more specifically, of new forms of territorial public regulation. We argue that territorial development policies, in a context characterised by the growing strength of local actors and the development of new instruments of public action (contracts, territorial plans, etc.), are contributing to the formation of new territories. From this perspective, one of the crucial questions is the capacity of these multiple actors, representing different social groups but working together on a single territory, to integrate divergent interests. While our empirical thinking draws primarily on French case studies, we will show that the question of the involvement of local actors in the implementation of territorial planning policies, and more specifically in the coordination of sectoral policies, forms part of a wider global trend in spatial planning and development policies, both at European level and in Europe’s different member states. This is evidenced, in particular, by the evolution of the concept of territorial cohesion within the European context and its implications for spatial planning and public action. The first section recalls in its broad lines the emergence of a European regional policy that seeks to incorporate the territorial dimension into the process of European integration. In the second section, we show that the emergence of this policy has been closely associated with changes in the regional policies conducted by the different member states which, despite their diversity, reveal converging global trends. The third section tackles the question of the implementation of territorial action that requires the coordination of a multiplicity of actors with potentially conflicting interests. It analyses the ways in which these different interests are integrated through a pragmatic approach to collective action, emphasising the methods whereby rules of action are co-constructed for a territory. Rather than taking a normative approach to issues of territorial governance, we shift the focus of analysis to the local (infra-regional) territorial scale, in order to observe the new forms of territorial public regulation. The fourth section applies this approach to the French case, drawing on two case studies of intermunicipal structures in the Île-de-France region.