The European Security and Defence Policy (ESDP) is understood as an important new "instrument" in the EU’s Common Foreign and Security Policy (CFSP) "toolbox", designed to respond to the contemporary security environment as well as to overcome the inaction and hesitancy of the past. The new dynamic created by ESDP is raising the profile and effectiveness of the EU internationally although it remains embedded in an unreformed institutional framework that struggles to capture the imagination of a broader public opinion. This paper discusses important issues, particularly from a parliamentary perspective, that should be discussed more widely if ESDP is to provide real added value in the pursuit of CFSP and be sustainable in the face of future external crises and internal political debate. This paper puts forward arguments on addressing the so-called double-democratic deficit where there is a need for improved transparency, debate and democratic scrutiny of ESDP, which will otherwise remain in the shadow of the constitution.