Assad isn't even the one in question now. In fact, this move has been of benefit to Russia, Iran, Turkey and Syria.
So, now, we really aren't even discussing the current situation.
Also, since we didn't really withdraw from there, it's almost a "moot" point... we did and we certainly didn't as well.
So, great if one argues to withdraw because there definitely has not been any full withdrawal and at the most, troops shifted around the region, going back in to camps we abandoned, sending in tanks.