The research paper analyzes the creation of complex combination of several international organizations in Europe, which are also sustained by the European Union (EU). The research argues that the current political and economic situation in the EU zone appears as a complex interdependence, which has also become attractive for the EU Neighborhood, especially for the Eastern Partnership. Furthermore, the European Union security experts talk more and more in light of the Kantian and Wilsonian ideas – cooperative security. In fact, the imaginary European complex interdependence has been also accompanied by cooperative security and defense commitments. Meanwhile, this research argues that the emerging European cooperative security and defense system has been evolving smoothly also due to strong collective defense guarantees during the last 60 years – the NATO factor. The European states, being in inevitable-long cooperation in the EU and NATO, have achieved a sense of common political-security identity and community, which is necessary for the long-term international cooperation and stability. Furthermore, this common political and security identity in Europe was achieved by democratic states with free market economies, which also attract the EU Eastern neighboring states. Meanwhile, at this moment to retain a global role, the EU community should not ignore this factor along with a timely-proved Euro-Atlantic security link.