He has gotten too big for his britches.
I think it is all part of a plan. Allow Erdogan to deal with his Maoist problem. Eliminate the belligerence of the Kurds in accepting they are part of Syria because God knows they are incapable of running a state. Make keeping peace a Russian problem since Syria is their vassal state. Push Iran out. Extricate us from the S-Show BamBam staged and then rushed into. Make ISIS prisoners someone else’s problem.