To measure the sturdiness of King Abdullah of Jordan against the tide of upheaval sweeping the Arab world, go to Tafila, an impoverished town tucked into a sandy bowl encircled by the Moabite Mountains 110 miles south of the royal seat of Amman. Outside the courthouse where four youths recently awaited trial on charges of cursing the king, a crime punishable in this hitherto deferential kingdom by up to three years in jail, one hundred protesters continue cussing the king, until the order comes from on high to let the four go.

Such protests are growing in intensity and geographic reach, degrading the royal stature with every chant. Last season’s innuendo against his courtiers and queen has become this season’s naked repudiation of the King. In September, demonstrators chanted S-S-S, a deliberately ambiguous call for both the regime’s islah, Arabic for reform, and isqat, overthrow. The protesters outside Tafila’s courthouse dispense with such niceties, spicing the crude one-liners with which Egypt’s revolutionaries toppled Hosni Mubarak with cheeky Bedouin rhyming couplets: “O Abdullah son of Hussein/Qadaffi’s a goner, whither your reign?”

Among the flashy young men who staff the royal court, it is common to dismiss the protests as coming from unruly poor peasants after money and jobs. But in the more sober milieux of their parents where much of Jordan’s business is conducted, the King’s inability to impose his will on the south is a cause of greater unease. For though peripheral and small in number, comprising 10 percent of the kingdom’s six million subjects, the tribesmen dominate the ranks of his security apparatus. If their dissatisfaction grows, some might be tempted, as in Egypt, to jettison their leader in order to preserve their power. Doomsday may yet be far off, but, a former senior Jordanian intelligence official tells me, each month seems worse than the last. By way of comparison he cites Black September of 1970, when an armed force rose up against the King, only this time the forces challenging his rule are those already running the country, not Palestinians opposing it.

Under Abdullah’s father, King Hussein, the alliance between the monarch and his East Bank tribesmen was so sacrosanct that Jordan was often called the Bedouin Kingdom. Perhaps because the tribes seem so secondary to King Abdullah’s grandiose plans for modernization and economic expansion, he has had much less time for them. He and his Palestinian-born wife, Rania, have publicly campaigned against tribal law such as honor killing and actively forged a new patronage network, rooted in the Westernized urban high life of their mushrooming capital.

Beyond their immediate playground in West Amman lies a conurbation stretching twenty-five miles and incorporating over half of Jordan’s six million people, the great majority of them Palestinian (but now…