>>/42437/
I think he wants to expand his sphere of influence, Syria would never submit to him under Assad and Turkey can only ever be a junior partner to Russia thus putting Syria in Russia's sphere not Turkey's(and given the state of Russo-Turkish relations that may not be in their interest). He will not get the whole of Syria by backing rebels but he does get a buffer zone at least. Although at what cost?
Also, Turkey has been furthering efforts towards control of the Mediterranean as well, though I don't think Syria is much of a threat to this(although maybe as a Russian proxy they could be) so I can't say how much that contributes.
>>/42462/
> And I saw predictions from before that with Biden the wars and aggression will renew from the part of the US.
He is bringing the US back into a more global mindset. He already rescinded Trumps plan to send home troops from Germany. So maybe it could lead to a war, however interestingly enough he did also state that he is going to stop supporting the Saudis in Yemen and try to force an end to that war.