During the latter half of the first millennium CE, Central and Eastern Europe experienced significant cultural and political changes. These shifts are often linked to the emergence of the Slavs, as indicated by written sources and the appearance of comparable archaeological patterns. However, scholars still disagree on whether these patterns resulted from population movements, cultural assimilation (Slavicisation), or a mix of both.

After the fall of the Berlin Wall and the collapse of the Soviet Union, Europe’s security architecture increasingly revolved around NATO and the European Union. This article examines why Russia remained outside that framework and how the loss of parity between former Cold War rivals shaped relations with the West, NATO’s eastward expansion, and the prospects for a more inclusive European security system.