The bilateral relations between the Islamic Republic of Iran and the Republic of Iraq, despite fluctuations and political-security crises, have experienced a growing trend of expanding interactions. It can be argued that over the past two decades, signs of a transformation in the pattern of relations from a security-centered approach to complex, multidimensional, and interwoven interactions have become evident. The purpose of this study is to explain bilateral relations and their transformation based on the theory of complex (and asymmetric) interdependence. The main research question is: how can the relations between the Islamic Republic of Iran and Iraq become resilient against endogenous vulnerabilities and third-party threats? The research hypothesis is that, in order to strengthen the resilience of bilateral relations through multidimensional interdependence, policies should focus on institutionalizing economic relations, expanding cultural and social cooperation, promoting environmental and service-oriented collaborations, reinforcing institutional ties while reducing personalization, and enhancing resilience against third-party states. These measures aim to: (1) create multidimensional and balanced relations; (2) move interdependence from an asymmetric toward a more symmetric form; (3) ensure that interactions become institutional, public, and transparent, rather than merely individual or security-based; and (4) establish new structures to deter external actors from undermining the relationship. In this way, greater trust will be generated on the Iraqi side, broader cooperation across all fields will emerge, and the vulnerability of bilateral relations will be significantly reduced. This article employs a descriptive-explanatory method, with data collected through library sources, academic journals, and reliable online platforms.