That's not true at all. :C
But I see your point.
Now this may seem like a biblical definition, but I am using it as merely a historical reference. Both Israel and the Arab states recognize Abraham as their father. He had two sons, Ishmael, from his maid and his firstborn child, and Isaac, his son from his actual wife, technically his real firstborn. Ishmael is the father of the Arabs, and Isaac is the father of the Israelites (modern-day Israelis) The birthright was divided between these two and there were poor relations between the two groups since their origin. Sorry to bring a religious source into it, but both sides would agree with this statement.