Syria has not capacity to stop Hezbollahs activity. No more than USA troops have capacity to stop Iraqi insurgents or Israel to stop Hamas activity.
And after Syria was forced out from Lebanon such "capacity" was reduced to zero.
Syria still has significant presence in Lebanon, although perhaps more under the radar than previously.
I join those here who opine that the target is Hezbollah. I dont think Syria will be attacked by Israel. Certainly not Iran.