Turkey moved troops into northern Syria to fight ISIL and drive Kurds away from controlling the entire Syria-Turkey border.
Turkey will have to strike a balance between the conflicting goals of Russia and the United States if it is to achieve its ambition of a "safe zone" in northern Syria and build on an incursion which gave it control of a thin strip of the border.
Where is the balancing? Russia wants Assad to survive and so wants Assad's enemies defeated. Attacking ISIL and the Kurds supports Russia's objective.
As for America, our objective is to defeat ISIL--not to defeat Assad. And defeating ISIL in Syria lessens pressure on Assad by defeating an enemy of Assad.
So Turkey fighting ISIL helps us, too. No conflicting goals there.
Sure, in theory we want Assad to go. But in practice our government is just trying to "pressure" Assad into negotiating an end to the civil war while making it clear that we see the defeat of Assad as a potential disaster if ISIL fills the void.
So don't think that Turkey is following our lead when they make this offer:
Turkey would be ready to join any initiative proposed by the United States to capture an Islamic State stronghold in Syria, President Tayyip Erdogan said in remarks published on Wednesday, as Turkish-backed forces took more Syrian land from jihadists.
Obama floated the idea of joint action with Turkey to capture Raqqa during talks between the two leaders at a G20 summit in China, Erdogan said, according to Wednesday's edition of Turkey's Hurriyet daily.
How does that conflict with Russia's objective? Where is the balancing?