While the United States is widely considered Russia’s principal rival in the Middle East, Saudi Arabia may well be taking second place. Moreover, not unlike Moscow’s suspicions toward Washington, Russian officials and analysts have often seen a Saudi hand in problems closer to home, in Russia’s neighboring countries and even within Russia itself. Russian-Saudi tensions thus seem unlikely to lessen anytime soon.

Some of the strains in Russia’s relations with Saudi Arabia derive from the kingdom’s long-standing role as one of America’s closest and strongest allies in the Middle East.

Yet, even as Saudi Arabia’s alignment with Washington frustrates Russia in some areas, Riyadh’s differences with the United States — such as over its aid to Syrian militants that neither Washington nor Moscow find to be acceptable — create trouble in others.

Saudi Arabia’s Cold War-era cooperation with the United States in supporting Afghanistan’s mujahedeen fighters against the 1979 Soviet invasion is the foundation for much of Russia’s distrust of Saudi Arabia. This is less a historical grievance, however, than a long-term and continuing problem for Russia, in that it ultimately contributed to a civil war in post-Soviet Tajikistan, an ungoverned Afghanistan exporting extremism, the spread of terrorists and drugs across the Eurasian space, and — after the attacks of Sept. 11 — a long-term US and NATO presence in Central Asia.