The purpose of this paper is to consider a certain number of external regional actions and identify any potential changes in the balance of power between central government and regional authorities. Four channels of regional activity are analyzed: decentralized cooperation, inter-regional cooperation, and the presence of regions in inter-regional associations and in the EU through their Brussels offices. It will be demonstrated, based on empirical data on the French region of Provence-Alpes-C?te d?Azur (PACA) and the Italian region of Tuscany, that a rebalancing of power has effectively taken place. The consolidation of certain practices in relation to the external actions of regions extends beyond formal constraints. It causes them to be strengthened, and, as a consequence, the State has to adapt. This adaptation is seen primarily in the tolerance for regions? external actions, then by their formalization. These de facto transformations therefore often result in de jure formalization.