Its not a civil war because the bulk of the forces and the leadership attempting to depose Assad has come from outside of Syria from the very beginning.
Just like Iran, and just like Afghanistan.
By definition this has been an attempted invasion.
And you get this information where? I ask because your narrative is not based on facts. And much of the radical Muslims that were in Syria were brought there by Assad, as was the case with Saddam, by the way. These movements were created by those despots. Your problem is that you see only despotism as the solution. Yet it was the dictators who created and nurtured these monsters. And the dictator putin cannot and will not change that.