The European integration process has always been about security. Various integration theories explain the start of the process either as motivated by the need to deal with the old enmity between France and Germany in the aftermath of the Second World War or, more recently, as an attempt to create a basis for a viable European counterbalance to the Soviet Union in case the US were to withdraw from the Continent. The monetary integration of 1990s was advertised as a matter of war and peace. Member States that joined since the end of the cold war were often motivated by security considerations. However, when the provisions of the Treaty and their use are examined, a paradox emerges. There is no serious Common Defence Policy, let alone a European army. And even at the heart of the integration project, the single market, Member States have insisted on considerable autonomy when it comes to matters relating to security. Rather than actually pooling their resources, they have steadfastly sought to keep them separate, largely with the blessing of EU institutions. The argument of the present chapter is that the strategy of pursuing integration for reasons of security but then failing to integrate in critical respects, in particular when it comes to matters such as security related aspects of the internal market, is contradictory. If Member States want security through integration, they need to give up autonomy, and if they want autonomy, they cannot have security through integration.