The dissolution of the Soviet Union reshaped the geopolitical order of Eastern Europe and elevated Ukraine as a strategically pivotal state situated between Russia and the Euro-Atlantic sphere. This paper examines the Ukraine crisis as a manifestation of the re-emergence of classical geopolitics and great-power competition in Europe. It argues that while Russia has pursued a coherent strategic agenda aimed at maintaining influence in its near abroad, the European Union has struggled to formulate a consistent and forward-looking policy toward Ukraine. Drawing on geopolitical theory (Mackinder, Brzezinski) and contemporary international security literature, the study analyzes the evolution of Russia’s expansionist approach, U.S. security commitments, and the EU’s fragmented strategic response. The paper contends that the absence of a unified European agenda has contributed to prolonged instability, culminating in Russia’s full-scale invasion of Ukraine in 2022 and ongoing conflict through 2025. It concludes that a coherent European strategic framework—combining deterrence, long-term security guarantees, and political integration—is essential to shaping a sustainable European security architecture.