The West's public focus on the US-Russian competition in Syria misses one major factor: Iran is the country with the most significant interests and the most resources poured into Syria. Iran therefore holds the key to a settlement -- if there's going to be one.
Curiously enough, Russia and the US ease Tehran's burden for keeping its client and ally, Syrian president Bashar al-Assad, in power: Russia's Vladimir Putin, by bombing Assad's enemies; and the Obama Administration, by doing little to unseat him. Every little bit helps, as Iran is paying a multi-billion dollar price to keep Assad afloat economically while some of its Revolutionary Guards and allied recruits take casualties on the battlefield.
Iran's geopolitical interests dwarf Russia's and America's. Iran regards Syria as a lynchpin to its foreign policy and identity as a regional player. The Islamic State is the heir to a revolutionary movement that aspires to project power into the greater Muslim world, in particular the Sunni Muslim area of the Middle East.
Tehran already holds a dominant position in Iraq -- a gift of the Bush Administration, which overthrew Tehran's arch-enemy Saddam Hussein. Losing Syria would negatively counterbalance that achievement. Syria is key to Iran's influence in Lebanon through the Lebanese militia Hezbollah, to which it supplies arms and funds. Syria is a frontline state in conflict with Israel. In Tehran's view, Israel is but a cat's paw of American dominance in the Middle East.
All this means keeping a friendly Syrian government in power.
In comparison, US concerns are oddly minimal. The Obama Administration even once considered Assad a reformer. Since the end of the Cold War, no one paid much attention to Syria's ties with Russia. Successive American governments did little to upend Syria's -- and Iran's -- influence in Lebanon. If it wasn't for the Islamic State, President Obama wouldn't even be bombing Syria.
Russia desires to preserve its place in the Middle East maelstrom, keep its Mediterranean Sea naval harbor, sell weapons to Damascus and show up the United States. But the outcome in Syria is hardly existential threat to it. Other players -- Saudi Arabia, Persian Gulf countries and Turkey are all eager to corral Syria into the Sunni Muslim geopolitical sphere, although they all lived with a Syrian-Iranian alliance for decades.
So for all the outside involvement, Iran has the most at stake. Much of the fighting on Assad's behalf is done by combined Syrian and Iranian fighters, many sent in from Iraq, not to mention Hezbollah's key intervention.
Talks are underway in Saudi Arabia to forge some sort of agreement between the Syrian government and opposition groups to end the civil war. (Only the Islamic State is excluded.) Because Iran has the most to win or lose in the outcome, and has invested the most in Assad, success of negotiations depend almost entirely on its attitude. Is it really ready to jettison Assad, and more importantly, the security and intelligence services he controls? Unless the Iranians think he is going to lose outright, they won't. And that means more pain and destruction for Syria.