Britain has the greatest number of Islamic extremists linked to al-Qaeda of any Western country and poses a grave risk to international security, the US government believes.
Terrorist groups are using the UK as a base to plot terrorism attacks around the world, American officials have disclosed.
The level of al-Qaeda activity in the UK is a “major source of concern” in Washington.
American leaders believe Gordon Brown's government is failing to combat the threat of extremism among Muslims living in Britain.
“The UK has the greatest concentration of active al-Qaeda supporters of any Western country,” a senior US official told the Daily Telegraph.
“As a result, no Western country has been more threatened than the UK, but the UK-based al-Qaeda network poses not only a potent threat to Britain but to the rest of the world.”
The disclosure of American fears will increase Transatlantic tensions over the attempted terrorist attack on an airliner over Detroit last month.
The would-be suicide bomber, Umar Farouk Abdulmutallab, has said his attack was inspired and directed by al-Qaeda.
It has been claimed he was radicalised in London, where the bomber, a Nigerian, was a student between 2005 and 2008. British officials insist that he became a terrorist in Yemen.
American officials believe that European Muslims are more likely than their counterparts in the United States to subscribe to extremist doctrines.
The US prides itself on “assimilating” all immigrant groups into mainstream culture, while European nations including Britain have pursued a policy of multiculturalism. Critics say it leaves Muslims at risk of being alienated from wider society and susceptible to radical movements. (MS: Blaming multiculturalism again? Assimilation the only way? I respectfully disagree. Look more into what causes this "alienation from wider society" - does that just happen all of a sudden? No it does not.)
“The level of al-Qaeda activity in Britain is becoming a major source of concern,” said a senior State Department official.
“The organisation’s ability to use Britain as a base to plot terror attacks constitutes a serious threat to the security of Britain and other Western countries.”
The failed Detroit attack has renewed international attention on Britain’s record in dealing with international terrorism.
Abdulmutallab’s attack was the third al-Qaeda attempt to bring down a US-bound plane linked to Britain. In 2001, Richard Reid, from London, tried to explode a bomb hidden in his shoe on a flight to Miami.
In 2006, a plot by Islamic extremists to blow up transatlantic airliners using homemade liquid bombs was foiled.
Among some US politicians and security experts, the British capital has been dubbed “Londonistan” because of the presence of so many radical Muslims and mosques with connections to extremist preachers.
British universities are a particular concern. Abdulmutallab was president of the Islamic Society at University College London between 2006 and 2007, while he was studying for an engineering degree. UCL, together with many other British universities, has been accused of failing to stop radical preachers giving talks on campus for fear of being accused of Islamophobia. (MS: There IS a way to walk the line...but my suggestions may not be appropriate for the public sphere. Rest assured, it does not have to be one way or the highway.)
Although the July 7 attacks in London in 2005 were the only fatal al-Qaeda attacks in the UK, many other plots have been disrupted. In 2006, British police disrupted an al-Qaeda plot to explode liquid bombs on several Transatlantic airliners, an operation officers said could have killed thousands of people.
Jonathan Evans, the head of MI5, has said that his service was aware of around 2,000 radicalised Muslims in Britain who might be involved in terrorism plots.
The Security Service has not updated that number since, but American officials believe it is now even higher. (MS: Believe it.)
United States intelligence officers are also gravely concerned about the number of British Muslims travelling to Yemen to become involved in extremist activity. Yemen is emerging as a focus for international counter-terrorism, as intensive military activity forces al-Qaeda to reduce its activity on the Afghan-Pakistan border.
Yesterday, launching his party’s new national security strategy, David Cameron, the Conservative leader, suggested that immigration systems are allowing dangerous extremists to enter the UK.
“There’s not much point having tougher laws to deport people who are a threat to Britain if at the same time we don’t have a proper border police force to stop unwanted people from coming in,” he said.
The stark American assessment of Britain’s position is, however, at odds with the optimism of British officials.
Last year, the official UK “threat level” was lowered, and Whitehall officials have claimed that British intelligence agencies have identified every significant terrorist cell in the country.
Earlier this month, relations between London and Washington were strained over just what information about Abdulmutallab had been passed to the US authorities by British intelligence agencies.
Downing Street has said that more than a years ago, MI5 passed on “security information” about Abdulmutallab’s links to radical preachers. However, US officials have insisted that any information passed on did not identify him as a potential terrorist.