From the Summary: "The European Union (EU) is a political and economic partnership that represents a unique form of cooperation among sovereign countries. The Union is the latest stage in a process of integration begun after World War II, initially by six Western European states, to foster interdependence and make another war in Europe unthinkable. Today, the EU is composed of 27 member states, including most of the states in Central and Eastern Europe, and has helped to promote peace, stability, and economic prosperity throughout the European continent. The EU has been built through a series of binding treaties, and over the years, EU member states have sought to harmonize laws and adopt common policies on an increasing number of economic, social, and political issues. EU member states share a customs union, a single market in which goods, people, and capital move freely, a common trade policy, and a common agricultural policy. Seventeen EU member states use a common currency (the euro). In addition, the EU has been developing a Common Foreign and Security Policy (CFSP), which includes a Common Security and Defense Policy (CSDP), and pursuing cooperation in the area of Justice and Home Affairs (JHA) to forge common internal security measures. EU member states work together through common institutions to set policy and to promote their collective interests. Key EU institutions include: the European Council, composed of EU Heads of State or Government, which acts as the strategic guide and driving force for EU policy; the European Commission, which upholds the common interest of the Union as a whole and functions as the EU's executive; the Council of the European Union (also known as the Council of Ministers), which represents the national governments; and the directly elected European Parliament, which represents the citizens of the EU. […] This report serves as a primer on the EU and provides a brief description of U.S.-EU relations."
CRS Report for Congress, RS21372