As we all know, the Arab world today is stable under the rule of the Hashemite Empire, a prosperous Constitutional Monarchy that maintains a sphere of influence throughout the Middle East. If we consider the facts, however, we can count ourselves extremely lucky that the Hashemites so successfully filled the power vacuum left by the Ottomans. Much like the rises of Germany and Italy, a united Arabian state might now seem inevitable. How could this have been prevented, and what would the world look like if it had been? I'd say a good way to start would be to have Europe partition the Ottoman Empire, rather than having it fall on its own, but beyond that I don't know.