WASHINGTON — Khalid Sheikh Mohammed's claims that he was responsible for dozens of successful, foiled, and imagined attacks in the past 15 years relies on a loose definition of the word "responsible." Officials say Mr. Mohammed was key to some plots but a bit player in others.
The 31 on his list range from the hijackings of September 11, 2001, to others that current and former government officials say were more talk than concrete plans, such as a plot to kill President Carter and other former American presidents.
The officials spoke on condition of anonymity, noting Mr. Mohammed's activities are likely to be the subject of an upcoming military tribunal.
His confession, his first public statement since his March 2003 capture in Pakistan, came in a closed-door hearing in the newly established American tribunal process. A 26-page transcript of the Saturday session at Guantanamo Bay, Cuba, was made public Wednesday night.
While there apparently is some truth in the statement, several officials said, there's also an element of self-promotion. They view the claims as at least in part a rallying cry to bolster his image and that of Al Qaeda in the only venue Mr. Mohammed has left: a military courtroom from which the public is barred.
"I have never known a criminal — either terrorist or otherwise — that didn't exaggerate," said Michigan's Rep. Mike Rogers, a former FBI agent and the top Republican on the terrorism panel of the House Intelligence Committee.
Pentagon spokesman Bryan Whitman said authorities would decide the credibility of Mr. Mohammed's claims if he is tried. "These are his words," Mr. Whitman said.
The American government linked Mr. Mohammed closely to the attacks of September 11, and his statement said he was responsible "from A to Z." Officials believe his claim that he beheaded Wall Street Journal reporter Daniel Pearl with what he called his "blessed right hand." And he corroborates Al Qaeda's known interest in attacking embassies, London's Heathrow Airport, the New York Stock Exchange, and other targets.
But his role in some plots may be minor. Some of the plots were formulated in Al Qaeda's early years, when alliances among jihadists were even more fluid than they are today.
"If you look at him having a senior position in Al Qaeda, when he says he's responsible, it can be interpreted in a lot of different ways," said Ben Venzke, head of the Virginia-based IntelCenter, a government contractor that monitors Al Qaeda messaging.
In the Defense Department transcript, Mr. Mohammed said his statement was not made under duress. But Mr. Mohammed and human-rights advocates have alleged that he was tortured, and legal experts say that could taint all his statements.
"In light of the rambling nature of his statements, and the views of some that he is prone to exaggerate his importance, we cannot feel confident we know exactly the level of his involvement in various prior attacks," said Joshua Dressler, a criminal law expert at Moritz College of Law at Ohio State University.