#PanArabism has always been an obstacle of Palestinian liberation.
The '47 war showed how uncaring the Arab states were toward the Palestinians and prioritized their selfish territorial interests over defense. Their succeeding utter and spectacular failures in '67 and '73 (and in this one the Israelis were caught completely unprepared) shouldn't really be surprising. And then they realized far too late that the Palestinians should be the one leading their own liberation, rather than you know, the Jordanians, Egyptians, Syrians, or whatever Arab state out there.
Arabs have failed the Palestinians many times and they are still failing them to this day by refusing to offer them refuge and citizenship in order for them to live as decently as their brethren. They are accusing Israel of apartheid (which is true) yet end up doing the same thing when Palestinians end up in their country against all odds.