"...Why would 1.2 million Arabs agree with the UN's decision to give 55% of Mandate Palestine to 650,000 (mostly) European Jews?"
Their consent was not deemed necessary at the time by either the victorious Allied Powers who seized the land from the Ottoman Empire nor by the League of Nations.
The Arabs of Palestine were merely conquered subjects of the Ottoman Empire with no clear-cut national identity nor autonomy nor sovereignty of their own and they were (rightfully) judged as unorganized (in a political and national sense) and politically and socially incompetent to govern themselves as a sovereignty in the modern world.
So the people in charge of the region divvied-up the place and carved off a big slice for far more civilized immigrant-folk who showed some potential for turning the place into something worthwhile and productive for the first time in centuries.
It was the misfortune of the disorganized, disjointed tribal folk of the region in those former times to have never evolved (politically and socially) to a self-governing state or to have degenerated into such a state so as to make themselves vulnerable to such treatment by powers and peoples far more advanced and sophisticated than themselves.
Their descendants are still paying a price for that, although the end-game is fast approaching, as the last of them are being squeezed off their land and forced to move elsewhere.
It need not have come to that, and their Adversaries were still open to talks of a serious political settlement, right up to the time of the 1967 war, but, as usual, the Palestinians never miss an opportunity to miss an opportunity, and the moment passed - major concessions by the Israelis are off the table, and have been, since 1967 - and, from their perspective, rightfully so.
Next time, don't pick a fight alongside lying Arab neighbors who promise mountains (Redemption) but deliver molehills (defeat) - 1948, 1967, 1973 - and expect to emerge intact.
Vae victus.
Karma is a *****.
Perhaps in the Next Life the Palestinians won't allow themselves to degenerate and disintegrate so badly that they are considered politically incompetent and have Empires and Mandates and Leagues making decisions for them like children.
But that's the fate they're stuck with, in
this life.
It's over... time for the Palestinians to emmigrate, and move on with their lives and futures, someplace else, where they stand some chance of finding peace and happiness.
After 65 years, the world at-large is bloody sick-and-tired of listening to this shit over a sliver of land in a corner of the Med.
The world at-large just wants this to be over with, one way or the other, and the sooner the better.
The Israelis understand this as well.
Consolidation and mop-up operations continue.