<p>This paper seeks to critically re-evaluate the controversial geopolitical concept of Lebensraum, which was first used in its classic sense by Friedrich Ratzel and subsequently further developed by Rudolf Kjellén and Karl Haushofer as a critical component of German geopolitics. As one of the most notorious geopolitical terms of the twentieth century, Lebensraum played a significant role during World War II, serving as a foundational element for the expansionist geopolitical visions of Nazi Germany and Imperial Japan. Despite being discredited by the atrocities of the 20th century, the core logic of Lebensraum has shown a disturbing resilience, resurfaced in discussions on Neo-Eurasianism in post-Soviet Russia, while the Russia-Ukraine War attests to the persistent danger of such ideologies under new conditions. This paper aims to conduct a critical intellectual examination and comparative geopolitical analysis of Lebensraum, with the objective of providing deeper insights into the historical misuse of geopolitical ideas and remaining vigilant against the normalization of expansionist or imperialist logic in contemporary authoritarian spatial imaginaries.</p>