Mark N. Katz is a professor of government and politics at George Mason University, and is the author of Leaving without Losing: The War on Terror after Iraq and Afghanistan (Johns Hopkins University Press, 2012).

The Obama Administration has sought to enlist Moscow in the effort to increase pressure on Iran to cooperate with the international community and verifiably renounce any ambitions it might have to acquire nuclear weapons. But while Russia would undoubtedly prefer a non-nuclear to a nuclear Iran, joining the U.S. and its allies in more forcefully sanctioning Iran for not cooperating on this matter involves risks for Moscow that it doesn’t wish to incur. 

The geostrategic, economic, and political relations between Russia and Iran are, in a word, complex.  Historically, Russia and Iran have been geostrategic rivals. In the 19^th century in particular, Tsarist Russia made gains in both the Caucasus and Central Asia at Iran’s expense. In both the 19^th and 20^th centuries, Iran often had reason to fear a powerful, encroaching Russia (or Soviet Union) – an important factor underpinning the alliance between the United States and Iran from the end of World War II through the overthrow of the Shah in 1979. Even after the Shah’s regime was replaced by the virulently anti-American Islamic Republic, Soviet-Iranian relations remained tense – especially since Tehran regarded both the Soviet occupation of Afghanistan (1979-89) and Soviet support to Iraq in the Iran-Iraq War (1980-88) as highly threatening.

With the end of the war with Iraq and the Soviet withdrawal from Afghanistan, followed by the breakup of the Soviet Union itself, Iranian threat perceptions of Russia were greatly reduced.  Underpinned by certain common geostrategic interests, Russian-Iranian relations have been greatly improved since then. First and foremost among these shared interests is a common desire to limit American influence, especially in the countries of the Caucasus and Central Asia that became independent from the Soviet Union in 1991.  Another geostrategic interest which Moscow and Tehran share is a common fear of radical Sunni Islamist movements such as al-Qaeda and the Taliban which, in addition to being anti-Western, are virulently anti-Russian and anti-Shi’a. Yet another overlapping interest between Russia and Iran is fear and opposition to secessionism, which both states are vulnerable to it.