Russia’s recent use of an Iranian air base to bomb targets across Syria marks a striking new development in the history of Russian-Iranian relations. Throughout the 19th and much of the 20th centuries, Iran had unsuccessfully resisted Russian designs to control its land and influence its politics. Iran’s 1979 revolution was meant, among other things, to restore the country’s sovereignty against great powers such as the United States and the United Kingdom, and to stand up to the atheist Soviet Union.