“You need the charismatic dreamers like bin Laden to make a movement successful,” said Daniel Byman, a former intelligence analyst now at Georgetown University. “But you also need operators like Khalid Shaikh Mohammed who can actually get the job done.”…

But even as the United States prepares to put him on trial for carrying out Al Qaeda’s most successful operation, Mr. Mohammed is still considered somewhat of an outcast inside the terrorist network, rarely if ever mentioned in public pronouncements by Mr. bin Laden or his deputy, Ayman al-Zawahri.

Some terrorism experts believe that Mr. Mohammed will always be considered too secular — and too practical — to be completely accepted by the terrorist network’s senior leaders.

“As opposed to the rest of these guys who sit around and talk, K.S.M. actually got the job done,” said Mr. Brachman, the terrorism consultant.

“That’s what set him apart, and that’s what made him so scary.”