With the collapse of the Soviet Union and the removal of the Caucasus from the margins of the world’s political geography, the independence of the Republic of Azerbaijan, as Iran’s neighbor, created a historic opportunity to develop bilateral relations based on historical, cultural, and religious commonalities. However, instead of moving toward sustainable convergence, relations between Tehran and Baku have faced multiple challenges. Factors such as Baku’s secular policies, the downplaying of Shiite identity, the spread of Pan-Turkist ideology, and Azerbaijan’s growing ties with the West, Turkey, and the Zionist regime have contributed to the cooling of relations between the two countries.
In this context, the main research question is: What impact did the Second Nagorno-Karabakh War (2020) have on Iran’s national security and its relations with the Republic of Azerbaijan? The research hypothesis is that the security and geopolitical developments in the South Caucasus following the 44-day Karabakh war have confronted Iran’s national security with a set of multidimensional threats, including economic threats (such as the Zangezur Corridor), security–political threats (such as the increasing influence of the Zionist regime in Baku), and socio–cultural threats (such as the spread of Pan-Turkism and ethnic nationalism).
Based on the research findings, the hypothesis is confirmed; that is, the Second Karabakh War has not only exacerbated Iran’s two-decade-long security challenges but also would certainly have further cooled Tehran–Baku relations with the signing of the Azerbaijan–Armenia agreement in Washington in August 2025.