This book provides an overview of the relations of the EU and NATO through the case of Afghanistan. It examines the role of the International Security Assistance Force (ISAF) in conjunction with Provincial Reconstruction Teams (PRTs) and the European Union Police Mission (EUPOL) to evaluate the relations between the EU and NATO. The involvement of the ISAF and EUPOL missions from their establishment to evolution and the limitations of both missions in accordance with the management of the U.S. in the "War on Terror" are examined. The implications of U.S. policies for the missions of both parties are explored, from the first term of George W. Bush to the Obama administration. The book argues that while there has been co-operation between the EU and NATO without it being structural, thus being ad-hoc co-operation, the U.S. has been benefiting from this co-operation from the second term of the Bush administration to the Obama administration, thereby rehabilitating the tense relations between the EU and the U.S. In the final analysis, it may be said that this co-operation did not result in a success story in the case of Afghanistan.