The article investigates the distinctive features of the eastern external border of the European Union (EU) as an object of international political interaction. In the east, eight EU member states share borders with their four neighbours, including R

The article investigates the distinctive features of the eastern external border of the European Union (EU) as an object of international political interaction. In the east, eight EU member states share borders with their four neighbours, including Russia and Belarus, which account for two-thirds of the EU’s entire eastern border. It is obvious that at the current stage such a neighbourhood has become a great challenge for the European security and requires a change in approaches to the EU common policy of integrated border management. The paper analyses the dynamics of the EU’s eastern external border functions in the period before and after February 24, 2022. From the early 1990s to 2004, the functions of the borders evolved from rigid barriers to integration boundaries. After the largest EU enlargement in 2004, the configuration and the length of the eastern border line changed, and its filtering and regulating functions became decisive. The authors have evaluated the impact of the latest threats that arose as a result of Russia’s full-scale invasion of Ukraine on the changes in the ratio of the EU’s eastern external border functions. The barrier function has become dominant on the border sections with Russia and Belarus, and the integration function ‒ on the border sections with Ukraine and Moldova. It should be noted that the external boundaries of the EU serve as both state and common borders. The activities of border states aimed at coordinating efforts to monitor the EU’s eastern border and counter growing hybrid threats to international security are examined.