The adoption of the Defence package, including the defence inside the eu internal Market, raises the question of the role of the European Commission in this sensitive domain. This article combines a holistic security approach with the notion of field and not only sheds light on the Commission’s position in this field, but also on its relations with other actors in the establishment of the European Defence Market. Analyzing the practices and their effects, it is argued that this market is not the result of the convergence between national policies but a space of struggles and strategies among actors, state and non-state, to be well-positioned in European field of security and defence.