Statement of the Problem: Russia's full-scale invasion of Ukraine in February 2022 has profoundly disrupted the traditional mechanisms for managing regional order in the post-Soviet space, without any coherent alternative order having consolidated in their place. Research Question and Hypothesis: The central question is how the Ukraine war has affected the rearrangement of regional order in this space. The hypothesis holds that the war, by simultaneously eroding the material resources and the symbolic credibility of Russian hegemony, has transformed the previous hierarchical order not into a balanced multipolar configuration but into a fluid, multi-actor condition in which the regional states have expanded their room for manoeuvre. Methodology: The study is descriptive-analytical and framed within neoclassical realism; data were gathered documentarily for the period 2022–2025 and analysed through the six-phase thematic analysis of Braun and Clarke. Findings and Results: The Russia-led institutions face a dual crisis of effectiveness and legitimacy; Central Asia has pursued gradual, economically driven divergence while the South Caucasus has undergone sharper, securitised change; and China, Turkey and the European Union have each filled part of the vacuum without seeking full succession. The outcome is a renegotiated, eroded hierarchy.