Current events aside, the fundamental reason to favor the Palestinian cause over the Zionist project is not that the Israelis are Western and the Palestinians are not. That’s knee-jerk woke “decolonial” claptrap, which does the Palestinians no favors. There’s nothing inherently wrong with being Western, just as there’s nothing inherently right with being Eastern, Southern, or whatever. Regions are neither virtuous nor vicious. From time immemorial, non-Westerners have been as brutal, domineering, and interested in slave-holding/trading as Westerners. Slavery was the uncontroversial norm for millennia everywhere — including in the pre-Columbian West. It still exists in Asia. So the non-West gets no points on that count. On the other hand, the ultimately successful antislavery campaign arose in the West in the 19th century, not somewhere else. You don’t hear much about that. Kudos to the British and the founders of the North American antislavery societies.
No, the fundamental reason to side with the Palestinian cause is that the right to private property in land is legitimate. Sorry, socialists. For the most part, Palestinians had their land taken by force, as Zionist leader and first Israeli president David Ben-Gurion acknowledged. Today’s troubles flow from that.