If I were Israel, I would scoop up the Palis in Lebanon and transship them to Gaza. And then build a really high wall. At least you'd have all the Palis in one containment zone. The real Lebanese would be glad to see them go and should be willing help round them up.
You've got to remember that the PLO showed up in Lebanon only in the early 70's 'cause they got kicked out of Jordan (Cairo agreement). The Palis are the main reason that Lebanon was destabilized and then destroyed in the early '80s.