Disclosure of a top-secret presidential briefing is fueling new questions, just as the White House was hoping to set the issue to rest in an election year, about how seriously the Bush administration took the terrorist threat before 9/11.
In the document, the President's Daily Brief of Aug. 6, 2001, intelligence officials raised concerns about Al Qaeda activities - including the threat of hijackings - in the US.
It is true, as National Security Adviser Condoleezza Rice testified last week, that this "PDB" did not contain specific warning of the strikes that were to occur weeks later.
But the memo appears likely to amplify concerns that the White House responded passively when warned of a dire threat.
The finger-pointing over whether the administration lacked enough solid information to act could continue Tuesday, when the 9/11 commission will hear testimony then-FBI Director Louis Freeh and Attorney General John Ashcroft.
"The question is not whether you had enough specific intelligence to know where or when they would attack," says Jim Walsh, an international security expert at the Kennedy School of Government. "The question is: Did you engage a series of actions that would be sent throughout the system so you could protect yourself?"
While Dr. Rice was poised and unflappable in three hours or questioning last week, she repeatedly shifted responsibility to underlings, especially former counter-terrorism chief now uber-critic Richard Clarke, to make sure that presidential directives for more vigilance on terrorism were reached FBI field offices. "The responsibility for the FBI to do what it was asked was the FBI's responsibility," she said.
But a blame game is exactly what the administration didn't want. The White House originally opposed establishing an independent commission. But, pressed by 9/11 families, the commission was launched and now, as the campaign season heats up, it is still expanding its messy deconstruction of decisionmaking inside the executive branch.
Just 470 words long, the Aug. 6, 2001, PDB looms large in the 9/11 investigation because it's the one document that the president is sure to see. Until 6:05 p.m. on Easter eve, the general public had never seen the text of a PDB.
Pressed about the PDB last week, Rice described it as just a "historic document." Despite its title, "Bin Laden Determined to Strike at the United States," nothing in it signaled the 9/11 attacks or could have prevented them, she said.
But in two days of hearings with law enforcement and intelligence officials starting Tuesday, Democrats on the 9/11 commission are sure to press questions about why the Bush administration did not respond more forcefully to the threats the memo outlined.
"It [the Aug. 6 PDB] is obviously is of signal importance because of its timing and where it went," says Richard Ben-Veniste, a Democrat on the 9/11 commission. "That's where the issue of leadership comes. People who are in the top echelon of leadership in this country know that the FBI is a very difficult bureaucracy to deal with, and unless there is constant direction ... it will revert to its normal way of doing business."
Critics are focusing on four observations in this briefing, likely to come up in further questioning on the 9/11 panel this week:
• That Osama bin Laden had wanted to bring the fight to America for four years.
• That Al Qaeda members, including US citizens, had been in the US for years.
• That the FBI was reporting "patterns of suspicious activity in this country consistent with preparation for hijacking," including the surveillance of federal buildings in New York City.
• That in May 2001 an informer in the United Arab Emirates reported that a group of bin Laden supporters were in the US planning attacks with explosives.
All these observations challenge whether Bush administration officials can get by with saying no one knew what this meant or could have responded better to protect Americans on 9/11.
Already, national security experts are challenging whether that briefing was merely "historical."
"Condi Rice was being a little disingenuous when she said this was a historic document - that it wasn't current. Most intelligence estimates include history. History is what happened right up to yesterday. You always describe patterns and trends that lead you to a certain conclusion," says Judith Yaphe, a security expert at the National Defense University in Washington and former Iraq analyst at the CIA.
"If you write something for the PDB, it means there is a reason this has to be brought to the attention of the president.... I wrote enough to know why you write them that way," she adds.
Others say the document must be understood as just one of many national-security issues brought before the president.
"You get briefs like that every day," Richard Perle, a former Pentagon adviser, said Sunday on ABC. "There was not enough specificity to take action."
Still, critics' concerns are at the heart of the questions expected to be taken up when the 9/11 commission, formally known as the National Commission on Terrorist Attacks Upon the United States, questions top law enforcement officials in the Bush and Clinton administrations this week.
Experts expect that the FBI will bear a brunt of the criticism for failure to move on Al Qaeda operatives in the US in 2001. The congressional joint inquiry on the 9/11 attacks concluded that the FBI was "unable to identify and monitor effectively the extent of activity by Al Qaeda and other international terrorist groups operating in the United States."
More recently, former Rep. Tim Roemer (D) of Indiana reported that after thousands of interviews, "We have found nobody ... at the FBI who knows anything about a tasking of field offices" to step up investigation of the terrorist threat that summer.
"The FBI does have to answer this question that Rice put on the table so bluntly: Why don't you cooperate with the CIA and why didn't you before 9/11, when we know Al Qaeda had become such a serious threat to the US," says Michael O'Hanlon, a defense analyst at the Brookings Institution.
Critics say that, ultimately, the answer to that question goes all the way to the top of the Bush administration.
It's enough of a problem that Republicans are now worried the 9/11 investigation is turning into something like an impeachment hearing.
"Individual members have certainly displayed an attitude which is very troubling," says Sen. John Cornyn (R) of Texas, commenting on release of the briefing. "Even through the lens of hindsight, I find it difficult to see how anything in the briefing could or should have led to a specific action that would have prevented the tragedy of 9/11."
"It was inevitable that the 9/11 commission would get mixed up in presidential politics," says Larry Sabato, a political scientist at the University of Virginia. "The American people wanted a nonpartisan Warren commission, and instead they got a partisan Clinton impeachment hearing."
• Faye Bowers contributed to this story.