The purpose of this study is to elucidate to what extent and how the security dimension of European integration has been influenced by the international systemic changes since World War II and up to the present. For this purpose, first, the security understandings which have come to the forefront due to the international systemic change since the World War II are explained. Later the security dimension of European integration is evaluated in the context of security understandings coming forth in the international system. This study is important for two reasons. First, it reveals the historical evolution of security dimension of European integration in the light of international systemic change. These experiences may provide a new and original contribution to the literature. Second, the model which is used in the study shall provide an alternative to traditional models for those who want to analyze the security understanding of a state or a system.