This is the longest-running feud in history and goes right back to a guy named Abraham who had two sons, Isaac and Ishmael. Isaac was born to Abraham's wife, Sara, and Ishmael was the son of Sara's servant, Hagar.
The tribes of Israel were descended from Isaac while Ishmael, a forebear of the Arab races was treated pretty shabbily.
The resentment from Ishmael's descendants continues to this day.
Because of what Dozy said and what Harry Truman did. To the Muslim countries in the Middle East, Israel is like some spoiled, favored little brother or sister who always gets away with everything. Add to that the centuries of bitter hatred and the fact that, when it comes down to the Big Three monotheistic faiths, the Jews and the Christians seem to have no problem putting aside their differences to gang up on the Muslims, and it's no wonder it's such a mess over there.
I once had a Muslim friend put it like this: Your family lives in a house with all this beautiful land and one day a Jewish family comes loaded with guns and ammunition threatening you to get out. In her eyes, this is unforgivable. As much as I tried reasoning with her on this subject- telling her the past is the past and so on-she remained head strong in her beliefs.