World history is a shifting mass of appearing, growing and disappearing peoples and empires, sometimes through natural causes but mostly by foreign invasions. (Even the ancient Hebrews did not originate in what is today Israel but invaded from elsewhere and exterminated the local Caananite inhabitants).

Except to the "God-gave-them-the-land" crowd, there were no "rightful owners" and those portraying Muslims as illegitimate interlopers reveal more about themselves than about Muslims.

Only after WWII did the acquisition of land through war become universally unacceptable. The right to self-determination became also enshrined and thus began the process of decolonization. A reversal of that trend was the Partition Plan that carved a Jewish state out of predominantly Arab Palestine. Zionists naturally accepted Partition as it gave them a Jewish state they didn't have; the Arabs of Palestine naturally rejected it as it took half their existing homeland.