Newly declassified CIA documents reveal repeated pre-9/11 warnings of attacks on US soil

Osama bin Laden (File photo)

Newly declassified documents by the CIA suggest that they had repeatedly warned of possible attacks on US soil, including the possibility of an explosive-packed aircraft being flown into a US city, years before the September 11 attacks. The CIA on Friday released 71 intelligence reports prepared for the President's Daily Brief in the years before and immediately after the 9/11 attacks, offering a detailed chronology of what US intelligence knew about Osama bin Laden and al-Qaida as their threat evolved.

The collection, released as the US marked 25 years since the attacks, contains assessments dating from 1998 through September 12, 2001. While many passages remain redacted, the documents show that warnings about attacks inside the US, aircraft hijackings, Bin Laden's interest in unconventional weapons and the capabilities of his network appeared repeatedly in intelligence reports.

Multiple warnings

On September 10, 1998, a CIA assessment said Bin Laden's “preferred option” was to strike the US on its own soil in Washington. It also said the same group responsible for the bombings of US embassies in Africa “may fly an explosive-packed airplane into a US city”. The assessment cautioned, however, that intelligence provided no conclusive information about Bin Laden's intentions for future attacks.

The warning was not an isolated one. A July 1998 intelligence report said Bin Laden was considering attacks in the US and noted that some of his followers had indicated a desire to bring the conflict to American soil. By December that year, another CIA assessment said Bin Laden and his allies were preparing attacks in the US, including a possible aircraft hijacking. It noted that members of the network had received hijacking training, although no group directly tied to al-Qaida had previously carried out an aircraft hijacking.

The reports also tracked Bin Laden's ambitions beyond conventional attacks. An assessment from February 1998 said he and other Islamic extremists had agreed to procure chemical, biological and nuclear substances from open markets, while noting that his financial network could assist such efforts.

At the same time, the CIA was following the relationship between Bin Laden and Afghanistan's Taliban rulers. A 1998 assessment said Taliban leader Mullah Omar defended Bin Laden's continued presence in Afghanistan despite pressure to rein him in, while the Taliban's dependence on narcotics revenues and financial support from Bin Laden complicated efforts to isolate him.

A July 2001 report said a Bin Laden operation expected to be imminent had been postponed, but preparations for other attacks could still be underway. By August 28, a CIA assessment described al-Qaida's operations as flexible and difficult to detect, noting that cells could choose their own timing and targets and that the organisation's compartmentalised structure could limit what its leadership communicated. The August 6, 2001 President's Daily Brief, titled “Bin Laden Determined To Strike in US”, was also among the documents released. The report had previously been declassified in 2004 following a request from the 9/11 Commission.

But the documents also illustrate the difficulty of turning individual warnings into a precise picture of the attack that was coming. The CIA was tracking multiple possible targets, attack plans and pieces of intelligence at the same time. In the months before 9/11, reports covered threats across several countries and regions, while separate assessments followed Bin Laden's network, the Taliban, possible attacks in the US and the group's operational capabilities.

Post-attack report

The first post-attack report, prepared at 4am on September 12, 2001, offered an early assessment of what had happened. It said mounting evidence indicated that Sunni extremists in Afghanistan and the Persian Gulf had recently been aware that Bin Laden-directed attacks were imminent. It also reported that Bin Laden had told Mullah Omar that he had operations in progress that would cause great damage to the US. One source said the attacks were the result of two years of planning and suggested the Capitol and White House may also have been targets.

The release also includes reports covering the Taliban's response, the international military reaction, the shutdown of civil aviation and the impact of the attacks on financial markets in the first hours after the strikes.

Taken together, the documents provide a chronological record of a threat that was repeatedly visible to US intelligence but appeared in fragments: a possible attack on US soil, aircraft hijacking, unconventional weapons, overseas operations and a highly adaptable terrorist network. The 9/11 Commission later concluded that the failure to prevent the attacks involved failures of imagination, policy, capabilities and management, with the most important being a failure of imagination.