New documents on UKUSA history
The released section of the document covers only the period from 1945 to 1980, and even that section is heavily censored (or redacted as the cognoscenti like to say).
Nonetheless, it contains a lot of interesting material, such as this tidbit noted on the National Security Archive's intro page:
After the end of World War II, with Soviet codes still unbreakable, the U.S. Army and Navy SIGINT organizations had relatively little to listen to. Johnson’s history reveals that as of mid-1946, the most productive source available to the U.S. Army SIGINT organization was French communications, which accounted for half of the finished reporting going to intelligence consumers in Washington.Interestingly, Kurt Jensen reports in his recent book Cautious Beginnings: Canadian Foreign Intelligence, 1939-51 (UBC Press, 2008) that French was also one of CBNRC's major targets in the early post-war period (a suggestion that was also made in John Bryden's Best-Kept Secret: Canadian Secret Intelligence in the Second World War, Lester, 1993).
The NSA document also contains what I believe to be the first officially released mention of the UKUSA Agreement[*] (Book I, p. 17-19). The document explains that "the British Dominions" were mentioned in the 1946 BRUSA Agreement, which laid out the basis of post-war SIGINT co-operation between the US and the UK, but the dominions "were not direct and immediate partners in 1946." "Thus," it notes, "the now famous UKUSA Agreement was not that at all; at least to begin with. How it became the UKUSA Agreement was a development that spanned another eight years." This development involved, among other things, the Melbourne Tripartite Conference of September 1953, which laid the foundations for full Australian participation in the SIGINT partnership. Page 19 of the history reports that "the name BRUSA was changed [to UKUSA] at British request a year later," i.e., in 1954.
[Update 30 May 2009: Matthew Aid's new history of NSA, Secret Sentry, confirms and adds to this picture. According to Aid, the post-war BRUSA agreement was signed by the United Kingdom and the United States on 5 March 1946; the agreement's name was changed to UKUSA in May 1954. This suggests (to me at least) that the agreement ought to be referred to as the UKUSA (originally BRUSA) agreement of 1946.]
The 1949 CANUSA Agreement also comes in for a mention in the document (p. 18), although almost all of the details, including the name itself, remain redacted. The following bit of information is provided, however:
[Redacted].But the United States was suspicious; Canada had just been through a major spy scandal, the Gouzenko affair (chapter 4), and USCIB wanted to go slow. Making matters worse was the head of the Canadian policy committee on COMINT, a rather prickly character [redacted] refused for several years to adopt some of the security procedures which the United States and Great Britain had agreed upon at the BRUSA Conference. Moreover, while the United States wanted a formal document on COMINT cooperation, [redacted] did not. After several years of very difficult negotiations, the two countries finally agreed to exchange letters between [redacted] and USCIB chairman Major General C.P. Cabell. Thus [redacted] won the battle of the legal documentation while the United States got its way on security procedures.Mr. Redacted was, of course, Department of External Affairs officer G.G. ("Bill") Crean, who was chairman of the Communications Research Committee during that period. It looks like my earlier post on the CANUSA Agreement may have been correct in its suggestion that this letter was the actual document that sealed the agreement. Independent historian Matthew Aid, who wrote the introduction to the NSA history on the National Security Archive website, believes that this letter is indeed the document. But he also says that there was a formal signing of the agreement in the fall of 1949. [More info here.]
*The only previous official mention of UKUSA that I am aware of was DSD Director Martin Brady's 1999 letter to journalist Ross Coulthart, in which he acknowledged that DSD co-operates "with counterpart signals intelligence organisations overseas under the UKUSA relationship." See here and here for the actual letter.
Update 1 January 2016: The security procedures were mostly spelled out in Appendix B of the agreement, the 1953 version of which you can read here. As it turns out, Appendix B is virtually identical to Appendix B of the UKUSA Agreement. This would appear to confirm that the U.S. did "get its way" on security procedures.