Abstract : This paper examines how the US should respond to an operational EU force and how such a force might impact US strategy in Europe and internationally. The assumption is that the EU will eventually find a way to organize, fund, equip, and direct missions for its new defense organization. The primary assertion is that the US should embrace the rise of Europe's new defense establishment and move to a cooperative security strategy with the EU regarding European defense issues. At the same time, the US should take advantage of the next several years to transition the force technologically and organizationally in order to maintain a significant edge over any future rise by the EU to superpower status. This will give the US the option to maintain a more aggressive, grand strategy of selective engagement in the international arena. Finally, the US should cooperate with the EU by sharing advanced defense technology. This move will help reestablish the close EU-US ties enjoyed until the end of the Cold War, promote compatibility in case of NATO's future demise, and help the US defense industry remain competitive in Europe.