This report addresses the following issues central to the debate over European security and the future of the broader transatlantic relationship that may be of interest in the second session of the 110th Congress: the specific security missions of NATO and the European Union and the appropriate relationship between the two organizations; the types of military forces that are necessary for NATO's role in collective defense and for the EU's role in crisis management; the appropriateness and compatibility of NATO and EU's decision-making structures and procedures to ensure that there is an adequate and timely response to emerging threats; and the proper balance between political and military tools for defending Europe and the United States from terrorism and weapons proliferation.