Some 50 years ago, six nations joined in the first European federation. Now, with the addition of 10 nations in 2004, the European Union (EU) comprises 25 countries with a combined economy nearly equal to that of the United States and a population half again as large. EU supporters claim the Union has brought peace to the continent and spread prosperity by eliminating trade barriers. But further integration suffered a setback last spring when French and Dutch voters rejected the EU's proposed constitution. Opponents used the vote to register concerns about high unemployment, slow growth and increased immigration. Supporters said the constitution would have made the EU a more workable federation. With the constitution shelved for now, the EU faces another controversy: whether to admit predominantly Muslim Turkey.

Kenneth Jost is Supreme Court editor, CQ Press; associate editor, CQ Researcher; and author of The Supreme Court Yearbook since the 1992-1993 edition.