Saudi Arabia frets that Egypt, its strongest Arab ally and a major recipient of Saudi funding, is falling under what it sees as the baleful influence of the Muslim Brotherhood.
Riyadh recalled its ambassador from Cairo at the weekend in a spat that underlines the misgivings of the robed princes who rule the world's top oil exporter and who have watched Egypt's revolution and its often chaotic aftermath with alarm.
They fear that political uncertainty in Egypt, which votes in a presidential election this month, may undermine a decades-old strategic bond between the two pro-U.S. Arab allies, a bond already shaken when Egyptians toppled their ruler last year.
"The Saudis viewed the ouster of (President) Hosni Mubarak as a very negative development," said Robert Jordan, the U.S. ambassador in Riyadh from 2001-03.
"They're concerned about the Muslim Brotherhood and the uncertainty of the leadership. And they're very sensitive at any hint that that movement could spread to Saudi or other Gulf countries."
Riyadh's recall for consultations of Ambassador Ahmed Kattan after protests outside the Saudi embassy against the arrest of an Egyptian lawyer in the kingdom may prove fleeting.
Egypt seems keen to have Kattan back, judging by government statements and reports in state-owned newspapers of Egyptians waving Saudi flags at the embassy calling for his return.
It was street protests outside the Saudi embassy last week that caused umbrage in Riyadh. Crowds were protesting at the arrest of Egyptian lawyer Ahmed El-Gezawi by Saudi authorities.
Egyptian activists said he had been detained for speaking out against ill-treatment of Egyptians in the kingdom. The Saudi authorities said he had been smuggling drugs.
Even if the diplomatic quarrel is smoothed over, it reflects the new fragility of a once-solid alliance between the most populous Arab nation and the richest.
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