One of the Left's favorite fairy tales.
Doubt ISIS could care less about "Palestinians". Any PLO/PLA led government would be just as "Haram" in the eyes of ISIS as the current Syrian and Iraqi regimes.
(And beyond the region, of course, the idea that Boko Haram in Nigeria or Thai/Fillipino Islamic terror groups care a damn about "Palestine" is ridiculous on its face.)
Tell me how the “Palestinians” will defend their state against something like ISIS. Is the UN going to jump in and occupy?