Syria helped overthrow Saddam (their enemy). The Gulf Arab states financed the Sunni radicals in Iraq because they feared a Shia state. So your point is wrong and an attempt to protect the real backers of ISIS - the Gulf Arab states.
I think you are partially incorrect. I for one am quite happy that Russia is propping up Assad. He just sorta sucks, mostly by his succor of Hezbollah.
But he is orders of magnitude better than ANY of the rebel forces. So I will be cheering on Su-24s blasting jihadis.
But I think you are incorrect. Syria did not help depose Saddam. In fact Syria was a conduit for jihadis, IEDs, a hiding place for Chemical weapons, etc.
And you are 100% correct, the Gulf States created ISIS. In fact they bought weapons that we smuggled from Benghazi, to ISIS by way of Turkey. ISIS is pure Sunni.