In his recent visit to Iran tried to get Turkey out of Irans targets. Iran will strike Turkey if she helps NATO and Turkey cannot do otherwise than to help NATO. Russians can strike from the North and from the south. Iran and Russia are badly cornered by NATO. Russia has no sympathy for Iran but Turkey is for decades a US puppet state and the Russians can't afford a US regime in Iran aswell.
from the article: Report: Two Russian warships to visit Syria