Israel isn't run by a simian clown and they punch back very, very hard.
Few things:
a) Israel is the king of gathering Intel on planned attacks. They were the ones who alerted germany recently of a planned ISIS attack.
b) As andy said Israel does not fuck around, they don't stop doing preemptive strikes regardless were it is. Yesterday they destroyed a few shipments of rockets next to Damascus that was headed to Hezbollah.
c) Israel has been dealing with the Islamic problem for a long time. They are not about to stop slaughtering terrorists because some politically correct college professors think they should massage hamas and hamas will like them. YES, there have been civilian causalities but this is the case with any war.
d) ISIS knows Israel knows Syria better than the entire coalition combined. Israel bombed syrias nuke reactor in 07 and has been watching that country for decades. If ISIS attacks Israel my guess is within a few hours all parts of syria that are ISIS controlled will be flattened regardless who is there. Yes, it is terrible to think about that however that is how Israel operates, just ask the Iraqis, in 1981 going against Americas wish Israel wiped out all of Iraqs nuclear systems.
I know the idea that Israel is strong and ruthless to its enemies will anger many Anti Semites here, but it is what it is, if you have the urge to get angry get angry over something you can so something about.
For anyone with even a small tiny brain, the idea that ISIS is the mossad or funded by Israel is absurd. However to people who are busy buying canned tuna and rice from Alex jones, it makes perfect sense that ISIS is really Israel, after all ISIS stands for Israeli Special Intel. Services, yup, millions of medicated idiots believe this.
I will say this thou, I do not think Israel minds that a bunch of Islamic fucks are slaughtering each other.