One of the main questions for the assessment of the usefulness of a strategic triangle as an analytical concept for understanding security relationships in the transatlantic area concerns the role of the European Union. The aim of this chapter is to provide some insights for understanding the role of the EU, in particular concerning the development of its military capability. In order to do this, we first need to investigate how member states within the EU view this process and what role it plays in the national context. Only with an understanding of the internal significance of the EU in this area may we assess its external importance.