This is a NAVAL POSTGRADUATE SCHOOL MONTEREY CA report procured by the Pentagon and made available for public release. It has been reproduced in the best form available to the Pentagon. It is not spiral-bound, but rather assembled with Velobinding in a soft, white linen cover. The Storming Media report number is A398983. The abstract provided by the Pentagon follows: Since 1999, the member states of the European Union (EU) have been pursuing capabilities to conduct conflict prevention and crisis management operations. The EU has no intention of usurping NATO's role in collective defense; but it intends to strengthen its influence in international politics and to acquire more options for crisis management. This thesis analyzes the EU's emerging role in the management of international security challenges and its implications for the future of NATO, the trans-Atlantic link and the EU itself. It explores the nature and scope of the crisis management role the EU intends to play, critically examines the prospects for the development of the requisite military capabilities in the EU, and assesses the impact of the EU's emerging role on NATO. From the standpoint of the United States (and other non-EU NATO allies, such as Norway and Turkey), close NATO-EU cooperation is imperative. The thesis concludes that the extent to which NATO and the EU coordinate their planning will be a decisive factor in the success of CESDP. The EU's emerging security role is a new test for the strength and resilience of the trans- Atlantic ties given formal expression in NATO.