Over the weekend, Russia emplaced a new, modified version of the S-300 (SA-23) air defense system at its naval base at Tartus in Syria. The system expands the range of Russia’s anti-air capability into Turkey and eastern Syria and comes after the collapse of a U.S.-Russia brokered ceasefire and the suspension of talks with Moscow over Syria. This system is similar to one reportedly installed on the Russian guided missile cruiser Moskva that had previously been deployed near the Syria-Turkey border. However, this marks the first time that Russia has deployed the S-300VM system outside of its territory. Moscow earlier deployed the S-400 anti-aircraft system in 2015 to the Russian air base Hmeimim near Latakia, Syria. The S-300 is a highly mobile system designed to engage aircraft, with some capability against cruise and ballistic missiles.