(CNN) -- The infiltration of a Middle Eastern terror network by a mole who helped foil a plot to blow up a U.S.-bound plane was a "phenomenal," "brilliant" and "powerful" success, experts said Wednesday. It's unclear how much of the credit should go to the United States or to Saudi Arabia, for whom sources say the mole was working, but both countries have delivered a practical and psychological setback to al Qaeda in the Arabian Peninsula, analysts on the region said. Western officials describe that affiliate as al Qaeda's most dangerous. "It's a devastating blow to al Qaeda, though not a fatal one," said Juan Zarate, who was deputy national security adviser for combating terrorism under President George W. Bush.
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Analyst: The intelligence success on bomb plot shows "the ability to get on the inside"
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It's "primarily a Saudi success story," another expert says
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Operation did not lead to the terrorist group's chief bomb maker, one analyst says
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The leak that a mole was involved could damage intelligence efforts, experts say
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