While the US continues its supposed aerial campaign against ISIS, the Russians have upped the ante, stationing combat aircraft in Syria, in support of the Assad regime. Basically, Iran and Russia have agreed to support Assad for access to the region. Part of Russia’s support is sending fighter bombers (Su-30s) and attack aircraft (Su-25s).
Russia is also reported to have deployed some of its Su-24 attack aircraft. Less than two dozen attack aircraft is a fairly modest deployment, but if they’re willing to aggressively use the sorties they can generate, they can have a significant influence on the fight.