The main argument that is considered to answer such research question is that the national energy policies divergence prevents the achievement of the EU objectives proposed by the European Commission in the Green Paper published in March 2006. As a consequence, to analyse deeply which the main divergences are between national energy policies, the structure of the thesis will be divided into three separated but interrelated chapters. In principle, this study aims to prove that in both externalities there is no common national ground to create and protect the energy goals proposed by the European Commission. In brief, it is expected to test the hypothesis by confirming the lack of convergence in environmental and security of supplies instruments that prevent the achievement of European energy common policies. Such evaluation will be completed with a general assessment of the EC communication ‘An Energy Policy for Europe’ presented in January 2007.