I guess they will make all kinds of threats.
One of the articles I've scanned in the past 15 minutes or so (perhaps one of those I linked up there) mentioned your very point -- Israel has hit Iranian assets in Syria at least 1K times, and the Iranians have talked big about retaliation. They know that if they had a little too much success with that, Israel would knock out the Hizzies' missile stockpile (which they're obviously going to do anyway, but on their own schedule), or behead the Iranian mullahcracy while the rest of the region (even Assad) danced and sang.