Imagine if King Husayn had ruled for four decades not the rump state of Jordan but Saudi Arabia. The consequences would have been enormous for such varied matters as the containment of Ba‘thist Iraq, the Arab-Israeli conflict, and the stability of oil markets. Most profoundly, however, had a moderate like Husayn been in charge of Mecca and Medina, and disposed of those hundreds of billions in oil wealth differently, the reach of militant Islam would today be much more restricted.
Well, it could have been. It did not happen because of developments in the World War I era in the Hijaz (western Arabia), as Teitelbaum's thoroughly researched and lucidly presented study establishes. At that time, the great grandfather of King Husayn was the amir of Mecca, as his ancestors before him had been since 968. Although Mecca was a small and remote town, it endowed enormous prestige on its ruler, who in the 1910s was the Ottoman emperor. This fact had two contradictory implications: First, the town received more in revenues from the Ottoman Empire than it paid in taxes, to the point that Teitelbaum finds it "almost wholly dependent" on the goodwill of Istanbul and therefore particularly unable to break away from the empire. Second, the amir of Mecca's position had such prominence that for over fifty years already currents were swelling around him to declare himself caliph.
The impasse was broken when London appeared on the scene during the world war, ready at least partially to replace Ottoman gold; thus was the Hashimite Kingdom of Arabia born in 1916, the first independent state in Asia to emerge from the empire.
Despite British help, economic problems plagued this polity (in late 1914, for example, the amir's "principal worry was getting food to the Hijaz") and, Teitelbaum argues, these had a key role in its undoing at the hands of the rival Arabian state, the Saudi one to its north and east. By 1925, the Saudis destroyed the first Hashimite kingdom. Teitelbaum provides the (surprisingly) first account of the nine years of this state's existence whose importance has become apparent only in retrospect. He does it so well that one wishes the book were longer.