 Complete the following phrase:  The Maastricht Treaty, concluded in 1992 between the 12 member states of the European Communities, is the foundation treaty of the European Union EU. Formally the Treaty on European Union, it announced a new stage in the process of European integration chiefly in provisions for a shared European citizenship, for the eventual introduction of a single currency, and with less precision for common foreign and security policies. Although these were widely seen to presage a federal Europe, the focus of constitutional debate shifted to the later 2007 Treaty of Lisbon. In the wake of the 