Decision taken to act on one warning out of many in 'Threat Matrix'

War on Terrorism: Intelligence

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The FBI'S decision to put America on high alert for a new terror attack came after the agency's "Threat Matrix" showed the country faced a "big and credible" threat .

The "matrix" is a top-secret CIA-produced document delivered every morning to the senior national security and intelligence officials of the Bush administration. It is distilled from the scores of warnings of threatened terrorist action against targets ranging from embassies to shopping malls and sports stadiums received by various law enforcement and intelligence agencies around the country. Some of the threats are extremely specific, others are general.

Awarded the highest security classification (Top Secret/Codeword), the document details the most recent and most sensitive threats of possible hijackings, bombings or poisonings. According to The Washington Post, the document lists where the intelligence comes from – inter- cepted communications, walk-in sources, e-mails, the foreign intelligence services of friendly nations, telephone threats, or else human sources developed by the FBI or CIA. Only threats deemed to have some degree of credibility are included in this restricted document.

The paper revealed that one day after the 11 September attacks, the Threat Matrix contained 100 threats to state facilities in America.

Though nearly all the threats have passed without incident and 99 per cent turned out to be groundless, every day there are more threats to take their place in the briefing document. Assessing the credibility of the threats and whether or not they should be made public is one of the most difficult tasks for President Bush's security advisers – a threat issued to a specific location, such as a city or sports stadium, could create chaos and destroy livelihoods.

However, if news emerged that the authorities failed to act on a threat that was subsequently fulfilled there would be a scandal. The authorities make their decision by examining the Matrix and looking for patterns and specific details. It was such an assessment that led to the alert issued on 11 October and the most recent, issued on Monday.

In a recent interview, the Vice-President, Dick Cheney – who has been moved to a secret location since the new alert – said: "You have to avoid falling into the trap of letting it be a cover-your-ass exercise. If you scare the hell out of people too often, and nothing happens, that can also create problems.

"Then when you do finally get a valid threat and warn people and they don't pay attention, that's equally damaging. If you create panic, the terrorist wins without ever doing anything. So these are tough calls."

When specific locations are mentioned in the Matrix, the FBI informs local law enforcement agencies or – if overseas – the intelligence services of that country. It also regularly updates its embassies of any specific or general threats.

By the very nature of their task the authorities are often forced to waste their efforts chasing threats that seem credible but are groundless.

Earlier this month, a woman called authorities to say her patriotic duty meant she had to tell them that her Middle Eastern husband was planning an attack with friends on Sears Tower in Chicago. The threat sounded credible and the FBI detained her husband and friends. On the next Threat Matrix the CIA reported that the FBI might have broken up an al-Qa'ida cell.

Upon further investigation, the FBI learnt that the woman was angry with her husband, who had a second wife. Her allegations were groundless but agents found some of the people were involved in an arranged-marriage scheme.

"Instead of terrorism," one law enforcement official said, "we found an angry wife."