As far as I’m aware Palestine wasn’t a nation state. Secondly the UN has never said Israel has the right to exist. Thirdly, the Palestinians agreed to settle for the 1967 borders but reluctantly. They’ve never accepted it as being just. The Jewish state of Israel has always been a thorn. Hamas have every right to claim the whole land from the Mediterranean to the Jordan as Palestine. That’s different to claiming the right to exterminate all Jews which is what Israel is suggesting for Gaza.

Even though the Palestinians have never been happy with Israel’s land grab they have repeatedly negotiated in good faith when Israel has consistently broken its agreements. Your assumptions are all based on Israel being an honest broker while the Palestinians have been untrustworthy. The opposite is true.