US-British SIGINT Agreement Revealed

Harry Hinsley, Sir Edward Travis and Brig Tiltman, who helped negotiate the intelligence sharing agreement between Britain and the US, in Washington in November 1945

MIL INT's PhD supervisor, Professor Sir Harry Hinsley, seen here on the left, was a 'behind the scenes' player in the establishment of the 'diamond in the allied SIGINT Crown' - the 1946 UK-USA Agreement. While the existence of the agreement has been public knowledge for years, the text of the agreement was only released in 2010. The NSA released the text along with a useful catalog of early primary documents from its secret archives. A joint effort to the very end, GCHQ also released a series of related documents on the same day.

The Cardinal, Hinsley's war-time codename (he worked on naval codes at Bletchley Park), later became the Official Historian of British Intelligence in WWII. It was not until these source documents were revealed that MIL INT would learn the full extent of Hinsley's involvement in all of the critical meetings at the inception of allied SIGINT cooperation. To see a video of Harry in action click here. For an account of what it was like being one of The Cardinal's PhD students click here. Look back to this posting for more details and a bibliography of Hinsley's work. MIL INT is writing about this now because he did not find the above picture until tonight when he was researching a related project.