BRUSSELS – As Europe picks over the ruins of the mega-merger that would have created a world-beating new aerospace and defense giant, questions are being asked about the inglorious role that the European Union played in the fiasco. The European Commission’s failure to champion the $50 billion merger of the Franco-German European Aeronautic Defence and Space Company (EADS), owner of Airbus, and the United Kingdom’s BAE Systems is being seen as a crucial factor in the deal’s collapse.