This paper seeks to contribute to the literature on security communities and defense integration by positing and deploying a model of the constitutive relations between processes of change in an (established) security community and defense integration among the community’s constituent members. The paper historicizes the present state of European defense integration and contrasts it to the state(s) of the past. Indeed, the present is not the primary focus of the paper. However, we propose that the sound analysis of the current processes can be served by a theoretically refined historical interrogation of the kind we seek to conduct. The contemporary security arrangements give an impression of stillness and immortality while, in fact, they experience processes of change, illuminated by the more historical perspective, that may have significant effects down the road in terms of evolution of primary norms of common values, multilateral practice and the norm of communication that are the characteristic feature of security community.