The essay examines a few issues related to the crucial theme of borders in the contemporary world. Through the combination of ontological, political, and legal reflection, the article shows the need for a rethinking of the role of borders within the globalized world. The first part introduces the problem of the complexity of the border from its terminological analysis. The second part challenges the idea of the border as a simple object using some ideas from the debate in social ontology. The third part analyses the complexity of the border through the Foucauldian notion of dispositif. In part four, I apply the notion of dispositif to a particular border, namely the wall. In the conclusion, it is suggested that the problematization of borders implies the questioning of the spatial-political structures inherited from modernity. In this conceptual rethinking, the role of law is of primary importance and a global constitutionalism is an option that is as viable as it is necessary.