Snowden caused ‘enormous damage’

• The leaking of thousands of British secret files by U.S. spy Edward Snowden has caused “enormous damage” and handed terrorists the “gift” of being able to attack Britain “at will,” says the new head of MI5.

Andrew Parker, director general of the British Security Service, said exposing intelligence techniques had given fanatics the ability to evade the spy agencies. The Snowden files were published this year by The Guardian newspaper.

Mr. Parker used his first public speech since taking over at MI5 to issue a scathing attack on the Snowden leaks.

He warned Britain was facing its gravest terrorism threat, including from “several thousand” Islamist extremists who are living in Britain and want to attack the country.

Government officials fear the leaked material has resulted in a “guidebook for terrorists,” while there is frustration Mr. Snowden has been hailed as a hero in some circles. Sources have said they find it incomprehensible anyone could argue exposing spyagency techniques for tracking terrorists is in the public interest.

Leaks from Mr. Snowden are known to contain at least 58,000 Government Communications Headquarters (GCHQ) files and it is feared there could be many more.

It is not clear which other countries have had access to the documents.

The Guardian continued to expose the information despite government pleas not to disclose intelligence techniques.

Mr. Parker last night did not name the leaker or the newspaper, saying only, “It causes enormous damage to make public the reach and limits of GCHQ techniques.

“Such information hands the advantage to the terrorists. It is the gift they need to evade us and strike at will.

“Unfashionable as it might seem, that is why we must keep secrets secret, and why not doing so causes such harm.”

He said the details of the spy agencies’ capabilities was their “margin of advantage” over the fanatics.

“That margin gives us the prospect of being able to detect their plots and stop them. But that margin is under attack,” he said. He added reports from GCHQ were “vital to the safety of this country and its citizens.”

“We are facing an international threat and GCHQ provides many of the intelligence leads upon which we rely,” he said. With the spread of an al-Qaeda threat to more and more countries, the continuing danger of Irish terrorism, the emergence of the lone-wolf fanatic and advances in technology and cyber warfare, MI5 was now “tackling threats on more fronts than ever before”, he said.