Turkey wants a buffer zone inside Syria. But I don't believe Russia wants Assad to regain control of all of Syria as their basic objective. I think that Assad controlling western Syria sufficiently to give Russia air and naval bases is all that Russia needs. But Russia can't appear to think Assad doesn't need to regain all of Syria. But doing more than appearing to back Assad's goal of running all of Syria is mission creep.
Indeed, in order to keep Assad interested in maintaining a Russian military presence in Syria, Russia has an interest in keeping Syria splintered so Assad needs Russian support to stay in the palace.
Of course, that is apart from my confusion over why Russia thinks it needs a military presence in Syria at all.
And it is nice to see the author supporting the notion that Turkey has the advantage in a fight with Russia over Syria (as I've argued), which is contrary to a lot of shallow analysis:
Neither Russia nor Turkey can afford to clash directly with each other. Turkey historically has been outmatched by Russia’s military superiority, but the clashes in February and March showed that Turkish forces still can damage Russian assets via drone strikes, despite Turkey’s losing 10 drones over three days during the fighting. Indeed, in the Syrian context, at least some observers believe that Russia’s overall military superiority to Turkey “doesn’t translate into superior strength on the ground in northwestern Syria.” Or as the prominent American analyst Michael Kofman observes, “The correlation of forces is decidedly against Russia in Syria.”
Unless Russia nukes Turkey. But that drags in NATO which has 3 nuclear powers in it.
Turkey and Russia have an incentive to avoid a war over Syria without letting Assad know there will be no war over Syria. But they can't admit it:
Wag the Assad.