Historically, there were always Jews living in the land. The Jews who immigrated there from Europe paid exorbitant prices to buy land from the Arab people who lived there, who willingly sold their land and accepted the money from Jewish buyers.
Are you aware that during World War II, Britain had a volunteer brigade known as "The Palestinian Brigade." It was made up entirely of Jews (Arabs fought on the side of Hitler). There was the Palestinan Symphony Orchestra, which was a Jewish orchestra, and the "Palestinian Post," which was a Jewish newspaper.
As late as the 1950s, Arabs refused to be called Palestinians and declared that if there were such people, they were Jews!
I believe and understand the biblical scriptures to clearly designate the land was to belong to the descendants of Abraham, Isaac, and Jacob; the nation of Israel/the Jewish people, forever.