I don't like Assad, in fact I hate him. Having said that, I must admit that I'll always prefer an Arab Syria over a communist US-led puppet state that America is currently trying to build in NE Syria; even Assad is better than PKK.
So, I'd rather hope that we cooperate with Assad in this case. They should try to liberate the East parts of the country where PKK is pumping up Syrian oil. This is indeed a very attractive prize for Assad. In addition, Iran needs a land border crossing to Iraq as a bridge for all the stuff they're smuggling into Syria. You see, the coming days will be very interesting.