More than four out of 10 CIA operations to prevent attacks on US soil are now conducted against targets in Britain.
This has led to friction between British and American spies, with some US intelligence officers irritated that resources are being diverted to gather intelligence on suspects in their closest ally’s backyard. British intelligence officers do not know the identity of all the CIA informers and are uneasy about some of the uses to which the intelligence has been put.
MI5 as a whole is glad of the help, however, and works closely with its sister service. US spies share information when it concerns security in Britain.
Intelligence from CIA informers is believed to have helped thwart more than one terrorist atrocity on British soil. Information passed on by a CIA source in Britain was also instrumental in locating Rashid Rauf, a British-born al-Qaeda operative killed by a US air strike in Pakistan on November 22.
A British official said: “There is a great deal of CIA activity inside the UK. The CIA has been given a free rein to raise, handle and process from intelligence sources inside the UK.
“In many cases we do not know who their assets are. Several of the recently foiled terrorist plots inside the UK were uncovered by informants run by US source handlers. We’ve been able to interdict these plots.”
A former CIA officer who still carries out freelance work for the agency voiced the irritation of some American spies. “It’s certainly frustrating that Britain is an Islamist swamp,” he said. “You don’t want to have to spend time spying on your friends.
British security chiefs have long turned a blind eye to a CIA presence in Britain and, since the attacks of September 11, 2001, MI5 and the CIA have worked together closely to combat the threat from Islamist extremists. MI5 also tolerates similar operations by the Israeli agency Mossad, which briefs members of the London Jewish community on threats to their security.
However, US security chiefs have stepped up their presence in Britain in the past two years, as they think Islamist extremists there are the biggest threat to US security and fear MI5 may be swamped by the scale of the threat. They also fear al-Qaeda recruits could travel to the US under America’s visa waiver program.
MI5 director-general Jonathan Evans has estimated about 4000 people in Britain pose a direct threat to national security.
Bruce Riedel, a Middle East intelligence analyst for the White House National Security Council, said: “A great deal of concern about threats to the US homeland is based upon attacks coming out of the UK. The 800,000 or so British citizens of Pakistani origin are regarded by the American intelligence community as perhaps the single-biggest threat environment.”