The construction of EU security actorness has been accompanied by a narrative on security nexuses (internal-external, security-development, civilian-military, public-private) associated with the so-called ‘comprehensive approach’. The end of the Cold War enabled the explicitness of EU security actorness. The post 9/11 facilitated the reinforcement of previous trends (transnational threats, externalisation of ‘internal security’, interpillarisation) and the introduction of innovative tendencies (comprehensive approach, internalization of the Common Security and Defence Policy, interconnection of security nexuses). This paper focuses on the internal-external security nexus declared by the EU in the post-Cold War, and reflects about the rationale and effects of the European narrative and practices on the configuration of a post-Westphalian security actor. Based on the analysis of three expressions of the nexus, it is argued that the latter reflects a securitising move of the European actor explained by the convergence of opportunity (redefinition of security, prioritization of transnational threats in a globalized world, soft power enhancement in the post-Cold War), capacity (legal, organic and operational in the field of security, after the entry into force of the Treaty on European Union), and (ambition to have a) presence. The holistic approach underlying the logic of the nexuses is the result of a co-constitutive adequacy: appropriation of policies and instruments of a multifunctional actor for security purposes (security of the EU and of European citizens); securitization of issues in order to promote the policies and the actor.