The alarm was raised during a private briefing from a senior M16 official to visiting U.S. congressional members in 2008 on growing concern in America about British-born radicals who receive training and become "suicide operatives," The Daily Telegraph reported Friday.
British officials would be "hard pressed" to prevent an attack by home-grown terrorists, a counter-terrorism official in the Secret Intelligence Service said.
Details of the warnings and concerns were in diplomatic cables that are part of a cache of more than 250,000 U.S. State Department documents obtained and released by WikiLeaks and distributed to certain media outlets, including The Daily Telegraph.
During the April 2008 meeting, a top British intelligence officer told the U.S. delegation Britain faced threats from terrorists abroad and "internal home-grown" terrorists, making the situation "uniquely challenging," the leaked information indicated.
"Moreover, the internal threat is growing more dangerous because some extremists are conducting non-lethal training without ever leaving the country," the U.S. Embassy's secret record of the meeting indicated. "Should these extremists then decide to become suicide operatives ... intelligence resources, eavesdropping and surveillance would be hard pressed to find them on any 'radar screen.' [The intelligence officer] described this as a 'generational' problem that will not go away anytime soon."
Simultaneously, documents indicated the U.S. government was growing more frustrated with what it saw as British leaders' inability to appreciate an increasing threat from Somalia, where growing numbers of British Muslims reportedly received terrorist training, the Telegraph said.