This news on the Sept. 11 investigation… a veteran Army intelligence officer has told the New York Times that a secret military intelligence team repeatedly contacted the F.B.I. in 2000 to warn about the existence of an American-based Al Qaeda cell that included four of the would-be hijackers including Mohammed Atta. The officer — Lt. Col. Anthony Shaffer — said military lawyers blocked the team known as Able Danger from sharing any of its information with the bureau. Shaffer is the first military official to discuss this information publicly. Last week the heads of the Sept. 11 Commission announced that it knew about the Able Danger team but it concluded that it ’did not turn out to be historically significant.” According to the commissioners, the only claim that the military had identified Atta as a threat prior to the attacks came from a single Navy officer.