I don’t know if one can truly say definitively that the Arab race descends from Ishmael or not, I have read some things which do not back that idea up. However, I do agree with you about the hatred muslims harbor for the Jewish people. They hate the fact that they were “chosen” by God to bring about the salvation of the world. They also hate us Christians, because we believe that salvation is from the Jews. It’s something they cannot accept
Catholic theology teaches that Ishmael, the son of Abraham and the maid servant, is told by God that he will also be the father of a great nation. “Tradition” teaches that the nation that arose from Ishmael are the arabs but that is not taught as revelation or doctrine.