Jordan is a more vulnerable target because, unlike the U.S., it can be destabilized. For nearly a century Jordan has been a miracle of stability — an artificial geographic creation led by a British-imposed monarchy, it has enjoyed relative domestic peace and successful political transitions with just four rulers over four generations. Compared to Lebanon, Syria and Iraq, similarly created, Jordan is a wonder. But a fragile one. Its front-line troops and special forces are largely Bedouin. The Bedouin are the backbone of the Hashemite monarchy, but they are a minority. Most of the population is non-indigenous Palestinians, to which...