Originally Posted by Malbec
No thats way too simplistic as it depends on what type of Jew you're talking about.
The Jews who'd lived there for centuries are Arab Jews, culturally and racially very similar to their Muslim and Christian neighbours.
The British banned migration into Palestine after WW1 in an effort to prevent a demographic swing from the Jews forming a definite minority into a majority.
Despite this many Ashkenazi Jews predominantly from Europe and the US migrated into Palestine mainly using illegal methods. This trickle turned into a flood after WW2. When found by the British these guys were mainly deported to their countries of origin.
These Jews were responsible for the sudden surge in the proportion of Jews in Palestine prior to 1949, but few of them held legitimate papers for Palestinian residency and were therefore not by any means Palestinian.