Bomb "Syria": no,
Bomb ISIS in Syria (or Iraq or wherever else they present an inviting target): yes.
ISIS will not stop. They
cannot stop. A Caliphate has been declared.
Al-Baghdadi is the Caliph, it's not just that he may not want to stop,
he is not allowed to.
A Caliph/Caliphate cannot respect borders, a Caliphate covers the whole world. If he does, he is in error and may be deposed. He cannot decide that "that's enough, let's stop here", he is not allowed to. A Caliph is required to make conquest until the whole world is conquered.
This article has its flaws, but does explain neatly why ISIS and Al-Baghdadi will not stop:
What ISIS Really Wants - The Atlantic
To be Caliph, he must have "authority", which is usually held to mean territory. Without authority, there is no Caliphate. Drive Al-Baghdadi off his territory, and there can be no Caliphate.
Wipe them out.