True, the EU has been debating means of fostering defence cooperation for years, with little palpable results. Is it to be different this time? The current discussion has focused on the institutional set up, and has pointedly overlooked some of the more political questions. What is it for? What incentive can the EU offer Member States to bind themselves into mutual dependence? What is the added value? The sovereignty question is the elephant in the room here. Do member states give up what they perceive as core interest so far: the autonomy of decision making on the national level on military and defence industrial affairs? Should the discussion on PeSCo fail to answer this fundamental question, it risks heading down the same route as previous efforts and help cement the EU’s reputation as a talk shop rather than a serious player in defence.