The 1991 IGC has reformed the European Community and the nature of the host of relations between its Member States. It has created the European Union through the Maastricht Treaty. The central hypothesis is that reform seems not to have resolved fully the deficiencies in form and substance of the Community's politico-legal foundation. The analysis proceeds through the comparison of three aspects: the reform of the constitutional foundation of the Community carried out by the IGC; the changes in the nature of the relations between Member States in these areas of competence that are inalienable from their sovereignty, and the introduction of the concept of citizenship of the Union in order to consolidate certain elements of citizenship that were present in the Communitys framework. The conclusion reached is that the 1991 IGC has produced an entity of which the elements carry inherent contradictions; this tense nature appears to demand further reform.