Since the end of the Cold War, outer space has undergone a profound transformation from a largely scientific and symbolic arena into an autonomous and critical security domain in international relations. This study examines the nature of this transition and analyzes the implications of intensifying great-power competition in space for the stability and structure of the contemporary international order. It asks how, and under what conditions, outer space has evolved into an independent security domain in the post–Cold War era, and how this competition affects the current international system. The study argues that this strategic transformation is driven by the interaction of three key factors: rapid technological advances that have enabled the military and security utilization of space; the growing dependence of national security, sovereignty, and economic prosperity on space-based assets, which has elevated them to strategic targets; and the limited effectiveness of existing legal regimes in addressing emerging challenges associated with new actors and disruptive technologies. Using a qualitative, descriptive–analytical approach, the research draws on an in‑depth examination of relevant documents alongside the analysis of reliable quantitative data. The findings suggest that the interaction of these factors has transformed outer space into a domain of intense geopolitical competition, contributing to the weaponization of space, the acceleration of multipolar dynamics in the global power structure, the erosion of existing international regimes, and a growing risk of strategic instability and conflict. At the same time, deep economic interdependence and effective international institutions appear to function as moderating forces that help restrain the escalation of full‑scale confrontation. The study concludes that the future of space security will depend on the ability of the international community to balance the logic of geopolitical competition with the need for cooperation in establishing responsible norms of behavior, preserving the sustainability of the shared orbital environment, and mitigating destabilizing trends.