Putin Arrives In Tehran For Summit With Iranian, Turkish Leaders

Russian President Vladimir Putin arrived at Tehran's Mehrabad airport today ahead of a summit on Syria with his Iranian and Turkish counterparts.

The talks will focus on Syria's rebel-held Idlib province, where rival factions are currently preparing for what could be the conflict's last great battle.

With Syrian government forces backed by Russian air power readying an offensive against the insurgents in their last major stronghold, the United Nations has warned an assault could lead to a humanitarian catastrophe.

Beyond that concern, the three leaders will be seeking to safeguard their own interests after investing heavily militarily and diplomatically in Syria.