American intelligence agencies are increasingly keeping their British counterparts in the dark on key information, for fear those secrets could end up on full display in U.K. courts.
“The Americans have got nervous that we are going to start revealing some of the information and they have started cutting back, I’m sure, on what they disclose," Ken Clarke, the United Kingdom's justice secretary, said in a Wednesday interview with the BBC.
The countries included are the United States, United Kingdom, Australia, New Zealand and Canada.
But the American intel community has become wary about sharing sensitive intelligence with the U.K. ever since a 2008 court case forced the British government to disclose specific details on terror detainee operations.
Binyam Mohamed, a U.K. national, sued for the release of sensitive documents related to his imprisonment at American detention facility in Guantánamo Bay, Cuba.
He claimed the documents would show he was subjected to enhanced interrogation techniques, such as waterboarding, during his time in Guantánamo Bay.
Mohamed was detained as a terror suspect by the United States from 2005 to 2009.
In 2010, the U.K. courts ordered the documents held by MI5 and MI6, the British domestic and foreign intelligence services, to be made public as part of the case.
At the time, American intel officials said the case would not harm the long-standing relationship between MI5, MI6 and the CIA.
Regardless, the disclosure had a chilling effect on those ties, according to Clarke — an effect that neither intel agency has been able to shake since.
“I can’t force Americans to give our intelligence people full cooperation. If they fear our courts they won’t give us the material," Clarke said.
As a result, Clarke has proposed new "closed materiel procedures" that would shield certain information from the courts.
Deputy Prime Minister Nick Clegg has vowed to oppose the new rules, arguing British security services were not above the law.
However, Clarke said if the U.K. cannot provide those types of guarantees to the Americans, it could lose its most important ally in the war on terror.
“The problem we’re facing is the American’s can say if they want ‘We will give you with full cooperation all this intelligence material but can you assure us it will remain secret, can you assure us that your courts won’t reveal it?' " Clarke said.
“The alternative is that they don’t give you the intelligence [and] that’s ... a serious problem," he added.