State-Army Navy Communication Intelligence Board. The United States has been reluctant to include Commonwealth countries on an equal footing and has sometimes blocked the exchange of information with them. The 1946 agreement stipulates that the exchange of information would not be “detrimental to national interests”. Resulting from an informal agreement on the Atlantic Charter of 1941, the secret treaty was renewed with the adoption of the BRUSA Agreement of 1943, before officially entering into force on 5 March 1946 by the United Kingdom and the United States. In the following years, it was extended to Canada, Australia and New Zealand. Other countries known as “third parties”, such as West Germany, the Philippines and several Nordic countries, have also joined the UKUSA community.   The terms of a secret agreement, which has become at the heart of the special relationship between Britain and the United States, are published today more than 60 years after the agreement was signed by high-ranking military personnel. A GCHQ spokesman said last night: “The 1946 UKUSA agreement served as the basis for cooperation between the two countries during the Cold War and remains indispensable to protect the UK from current threats.” Colonel Alfred McCormack of the Special Branch of the Military Intelligence Service, Colonel Telford Taylor of Military Intelligence, and Lieutenant-Colonel William Friedman visited Bletchley Park in April 1943. The American trio collaborated with Commander Edward Travis (RN), the director of the British Communications Information Agency (COMINT); and shared its solution with the Japanese Purple machine.
 The 1943 BRUSA Agreement (Britain-United States of America agreement) was an agreement between the British and American governments to facilitate cooperation between the US Department of War and the British Government Code and the Cypher School (GC&CS). . . .