Following the Second Nagorno-Karabakh War, military and security cooperation between Turkey and the Republic of Azerbaijan has increased significantly. Focusing on these expanding ties, this article examines their implications for the geopolitical position and national security of the Islamic Republic of Iran. The central research question asks: What impact have Turkey–Azerbaijan military–security cooperation after the Second Nagorno-Karabakh War had on Iran’s geopolitical weight and national security? According to the authors’ hypothesis, these collaborations—by reducing Iran’s political and geopolitical influence, expanding Turkey’s military and intelligence activities along Iran’s northwestern borders, and promoting pan-Turkist ideas—pose multifaceted threats to Iran’s national security.
Employing a qualitative methodology and document analysis, the study draws on academic sources, official documents, and field reports to examine various dimensions of these relations within an integrated theoretical framework combining physical and ontological security. The findings indicate that the deepening of Ankara–Baku military and intelligence ties—such as drone technology transfers, joint military exercises, and strengthened security structures through collaborative initiatives—has constrained Iran’s influence in the South Caucasus and weakened its geopolitical standing. Moreover, the spread of ethnonationalist discourses in Azerbaijan and surrounding regions has generated escalating manipulated identity-based challenges for Iran. The conclusion underscore the need to formulate a comprehensive national strategy to restore regional balance in the South Caucasus and safeguard Iran’s national security—one that synergistically incorporates military, diplomatic, economic, and cultural components.