This report discusses the status of European Union (EU) enlargement and its implications for both the EU itself and U.S.-EU relations. It includes a history of the European Union, the process of enlargement, overviews of current EU candidates, prospects for future enlargements, and U.S. perspectives.

U.S. and European private stakeholders, concerned about slow growth, job creation, and increased competition from emerging economies, have urged Brussels and Washington to strengthen transatlantic trade and economic ties by reducing or eliminating remaining trade barriers and by cooperating more closely in addressing global economic challenges. A select group of these issues are examined in this report.

Seventeen of the European Union's 27 member states share an economic and monetary union (EMU) with the euro as a single currency. These countries are effectively referred to as the Eurozone. What has become known as the Eurozone crisis began in early 2010 when financial markets were shaken by heightened concerns that the fiscal positions of a number of Eurozone countries, beginning with Greece, were unsustainable. This report provides background information and analysis on the future of the Eurozone in six parts, including discussions on the origins and design challenges of the Eurozone, proposals to define the Eurozone crisis, possible scenarios for the future of the Eurozone, and the implications of the Eurozone crisis for U.S. economic and political interests.