How will the USA and the EU handle security and defense policy issues in the future? Are cooperation or confrontation more likely? Since the attacks of September 11, 2001, it has become clear that no state can combat new threats such as international terrorism or state failure alone. However, during the Iraq crisis of 2003, significant security policy differences emerged between the USA and Europe, as well as within the EU itself. Are American and European concepts of world order compatible? The author analyzes the opportunities and limitations of cooperation by qualitatively examining the contents of European and American security strategies, also considering their development. In addition to comparing security policy documents, the author investigates how significantly the foreign policy identities differ across the Atlantic. The extent to which the USA and the EU collaborate in implementing their security strategies is also examined. Finally, perspectives for a transatlantic partnership are presented.