In theory, most countries in South-east Asia have, since the 1990s, engaged in a decentralization policy aimed at setting up the form of "good governance" recommended by most cooperation and development agencies. The declared objective is to involve local communities in decision making and transfer responsibilities of drawing up and managing strategies to the centres of power closest to the local population so that they can take part in decision making and play a full role as citizens. Whether in mainland or maritime areas, the regional integration process in Southeast Asia is characterized by the State's preponderant role. The State's major weight in the building of these transnational areas is seen, not so much in the absence of private and local dynamics as in the lack of connection of economic and spatial strategies between the different actors. Illegal actors, of course, but also the private sector and migrants, build their own transnational spaces with different boundaries and nodes from those officially recognized, since for their development they rely on family, ethnic or company networks, often much older than the official structures. De jure and de facto regional integration are both at work in Southeast Asia. This paper deals with the impact of economic corridors on local communities (the development of informal flows, type of relationships between private actors and local communities transformation of regional mobility) and the unequal ability of local population faced with the multiplication of transnational project on their own territory to negotiate their future.< Réduire