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GuardianThe terms of a secret agreement that became the core of the special relationship between Britain and the US are released today more than 60 years after the deal was signed by senior military officials.
A six-page "British-US Communication Intelligence Agreement", known as BRUSA, later UKUSA, tied the two countries into a worldwide network of listening posts run by GCHQ, Britain's biggest spying organisation, and its US equivalent, the National Security Agency.
Though its existence has long been known, the agreement, negotiated in London in March 1946, is only now being published, and for the first time officially acknowledged, after freedom of information requests in Britain and the US. Under the agreement, the countries agreed to exchange the knowledge from operations involving intercepting, decoding and translating foreign communications, including the "acquisition of communication documents and equipment". In a passage which ensured that GCHQ's activities remained wrapped in official secrecy, the agreement states: "It will be contrary to this agreement to reveal its existence to any third party whatever."
Documents released – and available from today, and free for a month, at www.nationalarchives.gov.uk/ukusa – include amendments and annexes to the agreement. One, dated 1948, states: "The value of Communication Intelligence in war and peace cannot be over-estimated; conservation of the source is of special importance." It adds: "The time limit for the safeguarding of Communication Intelligence never expires."
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http://www.guardian.co.uk/world/2010/jun/25/intelligence-deal-uk-us-released