The creation of integrated, multi-modal transport corridors represents the modern equivalent of building empires and spheres of influence. The emergence of corridors such as the China–Pakistan Economic Corridor, the Middle Corridor, the Zangezur Corridor, the India–Middle East–Europe Corridor, the Lapis Lazuli Corridor poses a serious threat to Iran’s regional role and geopolitical standing, leaving the country exposed to geopolitical isolation. By being excluded from emerging corridors, Iran risks transforming from a strategic crossroads into a geopolitical cul-de-sac—resulting in outcomes such as a weakened regional role, reduced influence, growing isolation, and a shift in power toward a coalition of its rivals. Despite its favorable geographical position as a natural hub for transit connectivity, Iran has been systematically excluded from key trade corridors. This marginalization is largely the result of ongoing international sanctions and ineffective policymaking in leveraging the country’s geopolitical and geoeconomic potential. The central question of this study is how Iran’s geoeconomic isolation—resulting from the expansion of alternative international corridors—could affect the country’s national security?” In response to this question, the following hypothesis has been proposed: “The development of alternative corridors in Iran's peripheral regions, as a serious geopolitical threat, could alter the regional balance of power by undermining Iran's geopolitical role, reducing its regional influence, and leading to the country's geo-economic and geopolitical isolation in regional trade and security equations.” This research was conducted using a descriptive-analytical method and relies on statistical data as well as library resources.