Launching the Permanent Structured Cooperation (PESCO) and the European Defence Fund (EDF) constituted a turning point not only in relation to European integration in the area of security and defence, but also as the next stage of the development of international armaments cooperation. For this reason, the genesis of this type of cooperation deserves attention. The article presents the standard forms of international armaments cooperation in recent history and the reasons why states decided to participate in them. In this context, particular examples include the comprehensive Soviet-German cooperation in the field of defence industry development in the 1920s, allowing for the circumvention of the restrictions imposed on Germany by the Versailles Treaty, as well as Finnish-Estonian cooperation when it comes to joint development of defence capabilities. The main purpose of the article is to reconstruct the foundations which serve as models for initiatives related to cooperation in the area of armaments, undertaken by Western European states after the Second World War.