What stinks for me is the occupation of the West Bank that started in the 60s during the 6 day war. Initially it might be argued that the occupation was necessary as a defensive measure against Arab aggression ... but they haven't just stayed there ever since, they have built settlements for Israelis against all principles of International Law and the West has just turned a blind eye... whilst rapidly mobilizing and intervening when Iraq (and the ill judged Islamic caliphate (ISIS)) made similar attempts at land grabbing in the region ... not really difficult to see why the Palestinians hate Israel and the West, is it?
I don't know enough to answer your question. So where did the Israelis come from that now occupy the settlements, and being subject to possible atttack if I remember rightly in the early days, why would you move to a hostile area (settlement), unless of course they came from an hostile area originally (the Israelis that is).

... but the shortened version would be the US relationship with Israel ... lot of powerful Jewish influence in the USA.