It’s difficult to know, especially when you strip away the kind of glib rhetoric that the likes of Corbyn specialise in, and consider what could happen if his proposals were adopted. Israel is surrounded by countries representing tens of millions who want to see it smashed. The faux naïveté that claims otherwise won’t cut the mustard with the Israelis not least given Jews and Christians have been slaughtered and / or purged across the Middle East over the course of c20 (starting before Israel was established).
If it cedes ground occupied since the last time they attempted to do, I expect they feel that puts them at further risk.
The Palestinians are in a no win situation either - I mean Syria could have rehoused them decades ago, but it didn’t, indeed have perpetrated their own atrocities on refugee camps. Cyprus hasn’t left it’s northern population as a human sacrifice to contest the Turkish occupation, but Syria I guess is a different animal, as are other potential rescuers like Jordan.
Historical claims - well pick your poison. The Palestinian population are largely a legacy of the Islamic conquests, which displaced or subsumed natives at the point of a sword (some Christian populations remain of course, though if the rest of the region is a guide, wouldn’t last long after a Palestinian victory).
However, they have also been there 1300 years, even longer than the first British colonialists in Ireland, and natives who assimilated with them, and a lot longer than Europeans in the Americas. That can’t just be undone, and Israelis returned after centuries in exile can neither have their condition ignored, nor have it take precedence over Palestinians due to events from thousands of years ago.
Moreover, now that the PLO has been partially supplanted by an Islamist / Nazi death cult - which treats Palestinians abysmally, not least gays - any possibility of a settlement looks ever more remote. It was possible to imagine Israel and the PLO hypothetically reaching an agreement, but Hamas want to wipe out the Jews. And as I say, Jews and Christian’s have been chased all over, with renewed vigour as secularist dictatorships have toppled and Islamic rule ascended - though nowhere as barbarically as the Turkish secularists did either.
Israel is of course, the conflict and its atrocities aside, head and shoulders above anywhere else in the region as a modern liberal society. But the conflict exists, the atrocities exist, and they are part of the Israeli accounts, as it were.
Fuck knows how it ends. If the west ever abandons Israel it would probably end up in a genocide. If they don’t, it will just go on and on, with the Palestinians crushed between all sides. A mess - but then such messes exist around the world, and they go on, and on, and on. There’s sadly nothing unique about it, except for the very particular attention it gets, which remains mysterious.