Intelligence ties between London and Washington have been jeopardized by a British court's disclosure that a terrorism suspect was beaten and shackled in U.S. custody, diplomats and security officials said Wednesday.

Fears in the United States that Britain can no longer be trusted with secrets is prompting an urgent assessment of relations between the allies and — according to some sources — has already slowed the flow of sensitive information from the U.S.

Britain's Court of Appeal on Wednesday authorized the release of a previously secret summary of CIA documents detailing the treatment of former Guantanamo Bay detainee Binyam Mohamed. Mohamed was arrested in Pakistan in 2002 and, according to the British court, subjected to "cruel, inhuman and degrading treatment by the United States authorities."

Foreign Secretary David Miliband fought for two years to block publication of the seven-paragraph summary, insisting that would violate a long-standing rule that nations don't disclose intelligence shared by their allies.

The White House said Wednesday the British court's judgment "will complicate the confidentiality of our intelligence-sharing relationship."

Experts warn the ruling could hurt Britain's ability to defend itself against terrorism, and represents the most serious challenge to intelligence cooperation since double agents during the Cold War.

The court's ruling has also raised new questions about whether British spies were complicit in torture.

In a rare public statement — his first since October — MI5 director Jonathan Evans used an opinion article in the Daily Telegraph newspaper to stress the importance of British intelligence ties to Washington, insisting the relationship has saved lives in the U.K.

"We cannot protect the U.K. without the help and co-operation of other countries. The U.S., in particular, has been generous in sharing intelligence with us on terrorist threats; that has saved British lives and must be protected," Evans wrote, in Friday's edition. "We must hope, for our own safety and security, that this does not make them less ready to share intelligence with us in the future."

The released document is a judge's summary of 42 classified documents shared by the CIA with MI5 — Britain's domestic spy agency — during Mohamed's questioning in Pakistan in May 2002. Evans acknowledged it described "unacceptable actions," but rejected claims his agency had been complicit in the detainee's alleged torture.

Experts say that — following the disclosure — allies may no longer trust British assurances that intelligence information will be kept secret.

"I suspect that for some while at least, the U.S. authorities are going to be much less generous with the material they share and much more calculating about protecting their own interests," said Nigel Inkster, a former assistant chiefof Britain's MI6 overseas spy agency.

Some British diplomats say restrictions on the information shared with London by Washington are already in place. The officials, who demanded anonymity to discuss intelligence issues, said the U.S. would never withhold details on threats to life, but American officials probably are already withholding some information they would have shared before.

"This is more serious than the Cambridge spy ring, this is more serious than Robert Hanssen," said Bob Ayers, a London-based former U.S. intelligence officer. "This has the potential to be far more damaging."

Hanssen was an FBI agent caught in 2001 selling secrets to Russia. The Cambridge spy ring was a group of upper-class Britons who spied for the Soviet Union from the 1930s, exposing details of colleagues stationed overseas.

Any change in trans-Atlantic ties risks seriously undermining British counterterrorism efforts, experts say.

Inkster said that, to the best of his understanding, there isn't a single major British counterterrorism operation over the last decade that hasn't benefited from "game changing" assistance from U.S. agencies.

"The government has to think about the long term implications of the damage to trust in a relationship that has been pretty crucial to U.K. security over many years," he said.

Mohamed's case also focused scrutiny on MI5's insistence that it doesn't collude in torture.

In a draft judgment, the Court of Appeal accused the agency of withholding information from ministers and the judiciary, disregarding human rights and failing to disavow harsh interrogation techniques.

A paragraph containing the criticisms was removed from the final judgment after the intervention of government lawyer Jonathan Sumption, who argued in a letter to the three appeal judges that the claims were unsubstantiated.

"They will be read as statements by the Court that the security service does not in fact operate a culture that respects human rights or abjures participation in coercive interrogation techniques," Sumption wrote.

Evans said claims about the conduct of MI5 were "so far from the truth that it couldn

t be left unchallenged," and said he expected extremists would seek to exploit the criticism.

"For their part our enemies will also seek to use all tools at their disposal to attack us. That means not just bombs, bullets and aircraft but also propaganda," the spy chief wrote.

Lawyers acting for Mohamed - along with media organizations, including The Associated Press, who demanded the seven-paragraph summary be released - said they were unaware Sumption had been in contact with the judges. They said they plan to complain to the courts about his actions.