Details of Cold War pact with US made public

Details of the top secret Cold War spying pact between Britain and the US were made public for the first time yesterday.

The 1946 UKUSA Agreement set out sweeping arrangements for sharing almost all communications intelligence on foreign powers gathered by the two countries.

It took 60 years for the UK's Cheltenham-based Government Communications Headquarters to confirm that the deal even existed.

Now the text of the ground-breaking seven-page agreement has been made available online by the National Archives in Kew, west London.

Headed "top secret", the document sets out the terms for Britain and the US exchanging virtually all intelligence relating to intercepted communications of foreign governments and militaries.

The areas covered are listed as: "1) collection of traffic; 2) acquisition of communication documents and equipment; 3) traffic analysis; 4) cryptanalysis; 5) decryption and translation; 6) acquisition of information regarding communication organisations, practices, procedures, and equipment."

The pact stressed that the exchange of intelligence would be unrestricted, except when both sides agreed that specific information could be excluded.

"It is the intention of each party to limit such exceptions to the absolute minimum and to exercise no restrictions other than those reported and mutually agreed upon," it said.

Emphasising the utmost secrecy of the deal, another clause stated: "It will be contrary to this agreement to reveal its existence to any third party whatever."

The document was signed on March 5, 1946 by Colonel Patrick Marr-Johnson on behalf of the UK's London Signals Intelligence Board and Lieutenant General Hoyt Vandenberg for the US State-Army-Navy Communication Intelligence Board.

The UKUSA Agreement, which is unique in the Western intelligence world, formed the basis for co-operation between the two countries throughout the Cold War and into the modern day.

It was expanded to include Canada in 1948 and Australia and New Zealand in 1956.

Ed Hampshire, principal records specialist at the National Archives, said: "The agreement represented a crucial moment in the development of the "special" relationship' between the two wartime allies and captured the spirit and practice of the signals intelligence cooperation which had evolved on an ad-hoc basis during the World War II.

"As the threat posed by Nazi Germany was replaced by a new one in the east, the agreement formed the basis for intelligence co-operation during the Cold War."

Other documents released by the National Archives today cast light on how the UK-US intelligence-sharing relationship worked in practice.

Six days after the UKUSA Agreement was signed, the then-head of MI6, Major General Sir Stewart Menzies, assured the Americans that any security intelligence they passed on would be safe.

Minutes of a meeting held on March 11 1946 recorded: "Lessons had been learned in both countries and he was certain that, on both sides of the Atlantic, every effort would be made to resist the pressure to divulge our information.

"He hoped that the US and British authorities responsible for the maintenance of security would be able to help each other in resisting this pressure."

The newly-published files also illustrate how UK intelligence agents struggled with limited resources.