Russian troops on patrol in the eastern Syrian city of Deir el-Zour in September. Moscow's involvement in the conflict changed its course but is steeped in controversy.
(MAX DELANY/AFP/Getty Images) A Russian navy captain looks over the missile cruiser Moskva, on patrol in the Mediterranean Sea, on Dec. 17, 2015. Fighting a conflict far from Russian territory relies on Moscow's ability to project military force over considerable distances. Without a land route option, Russia relied on airlifts and its maritime transport capacity to move troops to Syria and sustain them. (LOUAI BESHARA/AFP/Getty Images) A Syrian man wields portraits of President Bashar al Assad and his Russian counterpart, Vladimir Putin. For Syrians who support the al Assad administration, Moscow's support has been well-received. For those opposing Damascus, the Russian presence has been punishing. (VASILY MAXIMOV/AFP/Getty Images) A Russian Sukhoi Su-35 fighter lands at the Russian Hmeimim air base in Latakia province, in the northwest of Syria. Moscow has used the conflict to promote its equipment, leading to lucrative foreign arms sales.
