82As regards the derogations permitted under Article 58 EC, it cannot be denied that the objective invoked by the Portuguese Republic of safeguarding a secure energy supply in that Member State in case of crisis, war or terrorism may constitute a ground of public security (see judgment of 14 February 2008 in Case C-274/06Commission v Spain, paragraph 38; Case C-171/08Commission v Portugal, paragraph 72; and Case C-543/08Commission v Portugal, paragraph 84) and may possibly justify an obstacle to the free movement of capital. The importance attached by Member States and the European Union to the protection of a secure energy supply can, moreover, be seen, for example, with regard to oil, in Directive 2006/67 and, with regard to the natural gas sector, in Directive 2003/55.