Introduction: The South Caucasus, a pivotal geopolitical chessboard in Eurasia, has faced a profound redefinition of its balance of power following the 2023 military shifts and the onset of 2025. The “Zangezur Corridor” project, rooted in Article 9 of the 2020 ceasefire and designed to connect mainland Azerbaijan to Nakhchivan via Armenia’s Syunik Province, has now intersected with a new intervening variable: the United States’ “Trump Road for Peace and Prosperity” initiative, formalized by Presidential Determination in August 2025. By transferring corridor management to Western consortiums, this plan has transformed a mere transit route into a mechanism for altering the status quo and imposing geopolitical suffocation on Iran. This study aims to examine the consequences of this intersection for Iran’s strategic interests and the redefinition of the regional balance of power. The central question is: How does the Zangezur Corridor, in conjunction with the TRIP plan, redefine the regional balance of power, and what security strategy should Iran adopt? By critiquing existing defensive approaches, the study also underscores the imperative of transitioning to an “active balancing” strategy.

Methods: This is a fundamental, qualitative study employing documentary analysis and a case study of the Zangezur Corridor. The theoretical framework is John Mearsheimer’s offensive realism, which explains power behavior in an anarchic system as the pursuit of relative power maximization and regional hegemony. Data were collected through library research, focusing on official post-2025 documents, notably the U.S. Presidential Determination and strategic reports from leading international think tanks. The independent variable is the “Zangezur Corridor project” (encompassing geographical, legal-managerial dimensions and actors’ goals); the dependent variable is “the balance of power and Iran’s strategic interests” (transit role, national security, political influence); and the intervening variable is the “TRIP plan,” acting as hegemonic software that amplifies the corridor’s impact. The timeframe spans from the Second Nagorno-Karabakh War to the new agreements of 2025 and their future implications.

Results and Discussion: The findings indicate that the Zangezur Corridor-TRIP intersection has generated three major shifts in Iran’s relative power: first, a transfer of transit control from the Russian supervisory model to Western regulatory oversight, channeling Iran’s alternative routes to the Black Sea; second, the direct entry of extra-regional actors near Iran’s northern borders, threatening national security through the severance of the border with Armenia and stimulation of ethno-nationalist currents; and third, direct competition between the Western-backed Middle Corridor and Iran’s North-South Corridor, undermining Tehran’s transit standing. Moreover, by internationalizing the security environment around Iran and making Washington the primary corridor regulator, the project renders a mere border-warning approach insufficient. Within the offensive realism framework, these developments mirror the tragedy of great power politics, forcing Iran as a status-quo power to engage in external and internal balancing.

Conclusions: The article concludes that safeguarding Iran’s interests hinges on transitioning from the current defensive posture to an “active balancing” strategy. This strategy rests on three pillars: asymmetric trilateral balancing with India and Armenia to restore Iran’s geo-economic power against the Western consortium; wedge-driving diplomacy within the Western coalition by exploiting the rift between Moscow and Washington (which seeks Russia’s complete exclusion); and internal balancing via an energy-security barter model with Armenia to consolidate an economic foothold in southern Armenia while circumventing sanctions. In this way, Iran can shift the game’s logic from “defending the border” to “raising the cost for the rival” and navigate the unfolding geopolitical crisis.