Upon his election as President, Mitterrand could not profess any real competence in relation to contemporary foreign policy decision-making. Although his ministerial past had brought him into close contact with francophone Africa, the world had changed beyond recognition in the twentyfive years that had intervened since then. Along with other leaders of the opposition, Mitterrand had been excluded from detailed involvement in, or information about, foreign policy-making. This was in accordance with the marked presidentialisation of decision-making in foreign policy affairs from the period of de Gaulle onwards. But he had also been a President-in-waiting for almost twenty years, and this had enabled him to refine his command of foreign policy and defence issues. As de facto leader of the Left after 1965, Mitterrand was called upon to respond to the great foreign policy and defence issues of the 1960s and 1970s, such as the development of the French nuclear deterrent, de Gaulle's repeated vetoes of Britain's application for EC membership, the withdrawal from NATO, and the Arab-Israeli conflict. The nearsystematic adoption of an anti-Gaullist stance on these issues in the 1960s gradually gave way in the course of the 1970s to the incorporation of key aspects of the Gaullist foreign policy legacy into Socialist doctrine. This occurred notably in relation to NATO, and the French nuclear deterrent. In this manner, Mitterrand contributed to the legitimisation of the Gaullist foreign policy legacy before his election as President.