The purpose of this chapter is to contribute to a better understanding of borders in Latin America, and how they are related to conflict over sovereignty. The chapter will present an account of the paradoxical process the borders in Latin America have undergone after being, during modernity, more or less subjective mode of delimitation of the political power that made possible the monopoly of legitimate violence and the constitution of semi closed spaces of social conflicts. These borders are now strongly called into question at the same time as they have become a strategic priority.