Reply #10: Some excerpts:

[Barrett808]

...But at the same time, five senior British officials said, the suspects were not prepared to strike immediately. Instead, the reactions of Britain and the United States in the wake of the arrests of 21 people on Aug. 10 were driven less by information about a specific, imminent attack than fear that other, unknown terrorists might strike.

...

Despite the charges, officials said they were still unsure of one critical question: whether any of the suspects was technically capable of assembling and detonating liquid explosives while airborne.

A chemist involved in that part of the inquiry, who spoke on the condition of anonymity because he was sworn to confidentiality, said HMTD, which can be prepared by combining hydrogen peroxide with other chemicals, “in theory is dangerous,” but whether the suspects “had the brights to pull it off remains to be seen.”

...

Two of the men, who were likely the bomb-makers, were conducting a series of experiments with chemicals, said the person briefed on the case.

MI5 agents secretly installed video and audio recording equipment inside the apartment, two senior British officials said. In a secret search conducted before the Aug. 10 raids, agents had discovered that the inside of batteries had been scooped out, and that it appeared several suspects were doing chemical experiments with a sports drink named Lucozade and syringes, the person with knowledge of the case said. Investigators have said they believe that the suspects intended to bring explosive chemicals aboard planes inside sports drink bottles.

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“The plotters received a very short message to ‘Go now,’ ” said Franco Frattini, the European Union’s security commissioner, who was briefed by the British home secretary, John Reid, in London. “I was convinced by British authorities that this message exists.”

A senior British official said the message from Pakistan was not that explicit. But, nonetheless, investigators here had to change their strategy quickly.

“The aim was to keep this operation going for much longer,” said a senior British security official who requested anonymity because of confidentiality rules. “It ended much sooner than we had hoped.”

From then on, the British government was driven by worst-case scenarios based on a minimum-risk strategy. ...