Months before the 9/11 attacks, former US President George Bush had received multiple briefings by intelligence agencies warning of an "imminent" attack on US soil by Al Qaeda but he did not take prompt action that could have prevented the tragedy, an op-ed in the 'New York Times' said.
Former reporter for the news daily Kurt Eichenwald said Bush had begun to get "direct warnings" about the possibility of an attack by Al Qaeda as early as the spring of 2001 but some in the administration considered the warning to be just "bluster".
The op-ed was published on the 11th anniversary of the terror attacks in which 3000 people were killed and thousands other injured.
"Could the 9/11 attack have been stopped, had the Bush team reacted with urgency to the warnings contained in all of those daily briefs? We can't ever know. And that may be the most agonising reality of all," Eichenwald said.
On May 1, 2001, the Central Intelligence Agency had informed the White House of a report that "a group presently in the United States" was planning a terrorist operation.
This brief was followed by another on June 22 that said Qaeda strikes could be "imminent" but the time was any attacks was not yet fixed.
"The president did not feel the briefings on potential attacks were sufficient and instead asked for a broader analysis on Al Qaeda, its CIA repeated the warnings in the briefs that were given to Bush in the following months," it said.
One brief on June 29 said operatives connected to Al Qaeda chief Osama bin Laden were planning "near-term" attacks that would have "dramatic consequences," including major casualties.
On July 1, a brief stated that the operation had been delayed, but "will occur soon".
Some warnings said while the timing of the attack was flexible, the planned assault was on track.
In one of the most "famous presidential briefings in US history", Bush received a classified review of threats posed by bin Laden and his terrorist network on August 6, 2001.
The brief was titled 'Bin Laden Determined to Strike in US,' a goal that was accomplished a few weeks later when Al Qaeda terrorists hijacked commercial airplanes and crashed them into the twin towers of World Trade Centre, the Pentagon and in Pennsylvania.
In 2004, amid criticism for lack of timely action on the warnings, administration officials dismissed the significance of the August 6 brief saying that despite the "jaw-dropping headline, it was only an assessment of Al Qaeda's history, not a warning of the impending attack".
"The White House failed to take significant action," the op-ed said.
"The administration's reaction to what Bush was told in the weeks before that infamous briefing reflected significantly more negligence than has been disclosed. In other words, the August 6 document, for all of the controversy it provoked, is not nearly as shocking as the briefs that came before it".
In the aftermath of 9/11, Bush officials had attempted to deflect criticism that they had ignored the CIA warnings.
The officials said they had not been told the exact location and time of the attacks.
However, Eichenwald points out that there were events that occurred throughout the summer of 2001 that might have exposed the plans, had the government been on high alert.
Months before the 9/11 attacks, a Saudi, Mohamed al-Kahtani, believed to have been assigned a role in the 9/11 attacks, was stopped at an airport in Orlando, by a suspicious customs agent and sent back overseas on August 4.
Two weeks later, another co-conspirator Zacarias Moussaoui was arrested on immigration charges in Minnesota after arousing suspicions at a flight school.
"But the dots were not connected, and Washington did not react," the op-ed said.