In the current strategic environment, with unprecedented challenges emanating from the South and the East – and from the within the structure of liberal political order, cooperation between the North Atlantic Treaty Organization (NATO) and the European Union is essential for providing protection of common values that are shared among liberal democratic states of the West. The security of EU and NATO are inter-connected; the 22 EU Member States are also NATO Allies, and, through their long-term coexistence, they have acquired values and principles that they consider to be a common good. They also have in common that each country has an interest in participating in the organization. The problem arises when the national interests of the Member States do not overlap at the intra-organizational level, that is, when the interests of NATO and EU are irreconcilable. The pursuit of meeting national interests by its member states has shaped NATO-EU cooperation since their inception, and will continue to do so in the future. The purpose of this paper is to analyze the dynamics of EU-NATO relationship in the broader context of international relations. So, that way – by getting the bigger picture – we try to determine the future of Euro-Atlantic relations.