In this report, trends in the development of the military aspects of the European Security and Defence Policy, ESDP, as well as in the North Atlantic Treaty Organisation are analyzed. Initially, a conceptual framework is presented. This builds on the difference between state and institutional influence, as well as on integration theory, balance-of-power theory and geopolitics. This report also highlights the developments of ESDP and NATO in the last few years. Regarding ESDP, there have been discussions on an autonomous crisis management capacity. Concerning NATO, the new command structure as well as the force structure, including NATO Response Force, are two important aspects. for both ESDP and NATO, lessons learned have been drawn from different operations. The situation in Iraq has been a major cause of turbulence in both organisations. The analysis includes areas of cooperation and disagreement between ESDP and NATO. The conclusions indicate that member will continue to play the most important role for coming developments, and that their choosing to act within the framework of ESDP or NATO will depend on the political circumstances of each potential operation.