The ongoing war in Ukraine has cast new light on the strategic partnership between Russia and Iran. Since February 2022, Russia and Iran have increased their defense and economic cooperation and publicly explored options that could transform the relationship into a broad-based strategic partnership. Iran's shift from a client to supplier state has reinvigorated debates about its defense capabilities and ambitions and introduced new questions about what Russian assistance could lead to in the future. Russia and Iran’s ability to maintain a cohesive partnership and to overcome sources of tension and competition will be a major determinant in both Russia's ability to sustain its military operations in Ukraine and the United States' ability to advance its interests in the Middle East.
To inform assessments of the implications of Iranian military assistance to Russia, the authors of this Perspective describe the factors that drive Russian-Iranian cooperation and examine how the relationship might evolve. First, they briefly survey Russian-Iranian relations prior to February 2022 and describe Tehran's initial response to the Russian invasion of Ukraine. Next, they examine how the relationship has evolved since the summer of 2022 and explore how the conflict has led to the deepening of ties between the two countries. Lastly, they identify indicators that U.S. analysts and military planners can use to assess the degree of cohesion within the Russian-Iranian relationship as it evolves.