Taking as a starting point the fall of the Berlin Wall, it is a question of clarifying the sequence of the process of unification of the Germans to West and East. It highlights the historical continuity of the Saar's reintegration process at the end of the 1950s, with the absorption of the territory and population of the former GDR, through the application of the same constitutional provision. Thus, without the opening of any constituent process and without the need to activate the conventional accession procedure, by assuming the extension of the scope of application of the LF, on the one hand, and the realization of an internal enlargement, on the other. Despite its mutation, unified Germany would remain one and the same subject of international law and one and the same Member State of the Union. The consequent constitutional formalisation of the synallagmatic commitment to the establishment of a European Union has already been confronted, at the very beginning of that Europe of between centuries, with incipient political disdain and punctilious sovereignty jurisprudence. The future of the integration process has, among other important factors, a key in the degree to which unified Germany assumes its responsibilities.