This communication addresses the case of the European security and Defence Policy (ESDP) and aims at demonstrating how the EU (with CSDP) offers an emblematic case of an international organization ensuring not only regulatory functions (or aiming at it) in international security, but also produces, through European defense policy, a policy symbol aiming at legitimizing the role that the EU intends to play on the international stage as a global player, particularly in the face of American power, even if the reality of this role will of course face the empirical practice of the EU international security. European defence policy is torn between the claimed intentions on the European level (reactivity to crisis, coordinated action…) the representations that the member-states develop around this policy. From a comparative perspective between France and Germany, the author analyzes this strain and demonstrates that ESDP fulfils latent functions as a political and symbolic substitute which is at least as significant, if not more, as its manifest functions of managing crisis. First of all, there’s a kind of torsion between European discourses around European defence policy and still diverging and nationally anchored representations in France and Germany on ESDP. Then a second level of strain originates between the military capacities proclaimed in the multiple European official documents and those really put at EU’s disposal by the member-states. Last but not least, a third level of torsion between European reality and discourses is the crucial issue of the legitimization of this policy before the national parliaments and public opinions. Eventually the legitimizing stakes of European defence policy tend to run up against the lack of a European common identity.