The story according to the House of Isaac unfolds as you say, but the story of the House of Ismael has a different bent. The Bible clearly states God intervened to save Ismael and his mother from the cruelty of Abraham (Ibrahim)who didn't love his first born son. Abraham was well out of the picture when God told Hagar that she and Ismael would survive to begin a great nation. And, as you say, if there will always be emnity between the Houses of Isaac and Ismael, how can you expect the Arabs to accept the Jews, when Scripture says that shall not be.
wg
PS - My apologies to the thread for arguing the absurdities of Scripture, but Mlsoft is the thread's best straight man, and he takes it all so gratiously.