Al-Qaeda, it seems, has gotten used to filling the No. 3 spot, an especially high-risk job that involves overseeing terrorism plots, recruiting, raising money and providing internal security.

“They know they’re going to be hit and they’ve planned somehow for it,” said Barbara Sude, a former al-Qaeda analyst at the CIA who now works as a political scientist at the Rand Corp. “We just don’t know what the bench is, or how deep.”…

Some U.S. officials said Yazid had a broader role and greater influence than any of his predecessors, and may be more difficult to replace. His background was in financing al-Qaeda and its operations, but over time he took on responsibilities for operational planning, propaganda, and managing the organization’s relationship with its burgeoning network of affiliates and partners, such as the Taliban.

“This guy had a much broader portfolio,” said a senior U.S. official. He was also a conduit to al-Qaeda founder Osama bin Laden and his No. 2, Ayman al-Zawahiri.