Rahman, a Libyan national, rose to the number two spot when Ayman al-Zawahri took the reins of al Qaeda after bin Laden was killed in May in a U.S. raid in Pakistan.
Officials did not say how Rahman was killed, but said it happened in Waziristan in northwest Pakistan where intelligence officials believe members of al Qaeda are hiding out.
"Atiyah's death is a tremendous loss for al Qaeda, because (Zawahri) was relying heavily on him to help guide and run the organization, especially since bin Laden's death," one U.S. official said.
"The trove of materials from bin Laden's compound showed clearly that Atiyah was deeply involved in directing al Qaeda's operations even before the raid. He had multiple responsibilities in the organization and will be very difficult to replace," the official said.
Another U.S. official said that "there's no question this is a major blow to al Qaeda. Atiyah was at the top of al Qaeda's trusted core."
Rahman ran daily operations for the group, spoke on behalf of bin Laden and Zawahri and was the one that "affiliates knew and trusted" and his death will make it more difficult for Zawahri to consolidate control, the official said.
"He planned the details of al Qaeda operations and its propaganda. His combination of background, experience, and abilities are unique in al Qaeda-without question, they will not be easily replaced," the official said.
U.S. Defense Secretary Leon Panetta said last month on a visit to Afghanistan that he believed the strategic defeat of al Qaeda was within reach if the United States could kill or capture up to 20 remaining leaders of the core group and its affiliates.More...