Since the last quarter of the twentieth century some traditional elements of state sovereignty have been questioned and, to a certain extent, eroded. Economic globalization, external interventions on humanitarian grounds in domestic conflicts, and supranational political integration in Europe, provide three major illustrations of this trend. In this new world, the state’s prerogative to define its own citizenship has remained a bulwark of sovereignty that virtually no state seems willing to abandon. Even in the European Union, where a majority of member states have agreed to abolish internal border controls and national currencies and have put common foreign and security policies on the agenda, member states remain in full control over access to their nationality in spite of formal establishment of a common Union citizenship by the Maastricht Treaty of 1992.