Congressman Curt Weldon has said that his storied career in the halls of power was destroyed for one reason - his claim that the 9/11 terrorist attacks could have, and should have, been prevented. 

Weldon, a ten-term Pennsylvania representative, 79, claims a secret CIA program named Able Danger identified and tracked lead hijacker Mohamed Atta and his infamous 'Brooklyn cell' of terrorists for over a year before the attacks. 

Analysts feared Atta was preparing to spearhead a major catastrophe, and those within the program had desperately tried to warn agencies including the FBI and the DOJ about the plot, but were systematically blocked from doing so, Weldon says.

And when the autopsy of the attacks was released by the 9/11 Commission in 2004, the Able Danger findings were nowhere to be seen. 

'America's got to realize that 9/11 is not what we're led to believe... I want the story to come out,' Weldon told the Daily Mail, ahead of the release of his tell-all book, Able Danger: What The 9/11 Commission Never Told You, on September 22.

When the 9/11 Commission Report was released, Weldon was vocal about how he would use his upcoming chairmanship of the Armed Services Committee to uncover the truth about the attacks. 

The position would have given Weldon one of the most powerful perches within Congress, able to launch subpoenas and hold public hearings to finally share what he knew behind closed doors. 

Three weeks before his expected re-election in 2006, Weldon's daughter's home was raided by the DOJ over claims of improper ties to Russian businesses. Weldon and his daughter were never charged with any crime, and he now says it was a 'deep state' plot to unseat him before he could expose the intelligence failings that led to 9/11. 

As the nation mourns the 25th anniversary of the tragedy, and after intelligence agencies have previously attempted to downplay and reject his allegations, Weldon says he is now ready to speak out. 

From the first moment hijacked planes flew into the Twin Towers 25 years ago, President George W Bush claimed not to know who was behind the attacks. It took nine days for Bush to publicly name Al Qaeda and Osama Bin Laden. 

But Weldon claims that within US intelligence, a small number of officials knew instantly who was behind it - because they were already tracking several of the hijackers.

Despite being a covert program, Able Danger was far from a small effort. As Weldon describes it, the project was an ‘innovative, multiservice, multiagency intelligence program’ that involved a large team utilizing incredibly expansive tracking software. 

‘Simply explained, Able Danger used supercomputers to mine and monitor the world’s internet worked databases - representing by volume and quality a treasure trove of unclassified intelligence unprecedented in history, a virtual world library, readable by supercomputers virtually instantaneously,' he writes in his book.  

Able Danger allegedly identified Mohamed Atta and his Brooklyn cell over a year before the 9/11 attacks, and analysts were terrified that plans for a major catastrophe were being hatched.

Weldon alleges that members of the Able Danger team attempted to pass this information to the FBI at least three times by late 2000, but claims that a 'wall' of bureaucracy and military lawyers blocked the transfer of the data. 

When Weldon first came forward with his claims about Able Danger, the Pentagon said it was unable to verify his allegations, and Defense Department spokesman Larry Di Rita said the project found 'mostly general references to terrorist cells' without directly naming Atta.

In 2006, the Senate Select Committee on Intelligence said that agents who claimed to see Atta on pre-9/11 intelligence charts were 'mistaken.' 

But Weldon - who at the time was serving as vice-chairman of the Armed Services Committee and the Homeland Security Committee - says he still believes claims about Able Danger's findings. 

He claims that his position in Congress led intelligence analysts to warn him about the Able Danger findings in the aftermath of 9/11, but those involved were 'harassed, shut down and lied about.

In 2006, Stephen Cambone, undersecretary of defense for intelligence, testified to the House Armed Services Committee that there were no verified formal requests for Able Danger information before 9/11, and no evidence showed intelligence sharing had been prohibited. 

But Weldon alleges in his upcoming book that those within the program told him they did exactly this, but faced a 'wall' of bureacracy and secrecy that prevented them. 

While the motives for the alleged information blocking remain shrouded in mystery, the former congressman blames a 1995 memo written by the Clinton administration’s Justice Department, known as the ‘Firewall Memo’, for standing in the way.

The memo’s author, DOJ official Jamie Gorelick, intended for it to set procedures for information sharing into the investigation into the 1993 World Trade Center bombing, to prevent intelligence gathered via secret Foreign Intelligence Surveillance Act (FISA) warrants - which did not require criminal probable cause – from being involved in criminal prosecutions.  

While this was ostensibly to protect the civil liberties of defendants, Weldon claims it became clear to him in his Congressional investigations that the memo acted as a bureaucratic ‘wall’ that prevented the CIA from freely sharing information with the FBI and other domestic agencies.

He claims that on at least three occasions, Able Danger team members allegedly tried to share intel with the DOJ that Atta and his Brooklyn cell were hatching a devastating plot in New York, but they were forced to cancel scheduled meetings each time.

‘Thus, the Able Danger team was prevented from fingering Mohamed Atta to the FBI, sacrificing the best chance to stop the September 11 catastrophe - and the wars in Afghanistan and Iraq - on the altar of political correctness,' Weldon claims. 

Weldon said his claims have been dismissed as 'crazy' in the past, but his upcoming book has since been endorsed by a number of officials, including Jim Gilmore, the former Governor of Virginia, and Erik Kleinsman, the former Chief of Intelligence in the US Army's Land Information Warfare Activity (LIWA).

The intelligence focus on potential Islamic terrorism within the United States was ignited in 1993, when Pakistani terrorist Ramzi Yousef detonated a truck bomb in the parking garage of the North Tower. 

Despite killing six people and injuring over 1,000, the attack was largely overshadowed by September 11. Within the intelligence apparatus, however, analysts knew it would not be an anomaly. 

In 1996, Weldon became chairman of the Research and Development Subcommittee of the House Armed Services Committee, a role that gave him oversight of upwards of $60 billion in defense spending. 

He funded intelligence technology databases that grew into the Able Danger task force, which was led by U.S. Special Operations Command (SOCOM) to plan against transnational terrorism. 

Speaking with the Daily Mail this week, Weldon said he has been left haunted by the knowledge that the greatest tragedy in American history could have been thwarted if this project's alleged findings were not 'blocked.'

He says he remains furious that his efforts to expose what Able Danger allegedly knew decades ago have gone unheeded, and accused intelligence circles of 'manipulating people to make anyone questioning it look like they're crazy.'

Weldon is now calling for a new presidential commission on 9/11, with similar efforts already gaining traction in the halls of power as Wisconsin Senator Ron Johnson has backed plans to pursue new hearings. 

'I want a commission that has integrity,' Weldon said. 'Let a commission thoroughly investigate this and look at everything.' 

The Daily Mail has contacted the FBI, CIA and Department of Defense for comment on Weldon's allegations about significant intelligence failures in the lead-up to the 9/11 attacks.