Five Eyes

The intelligence-sharing alliance of the US, the United Kingdom, Canada, Australia and New Zealand.

The CIA glossary uses the name Five Eyes and describes the alliance as an intelligence-sharing arrangement between the US, Australia, Canada, New Zealand and the United Kingdom.¹

The alliance has its roots in cooperation in signals intelligence (SIGINT). According to the NSA, in March 1946 the United Kingdom and the US signed the UKUSA Agreement (originally BRUSA), which remains the basis of their cooperation in this field; it was later extended to Canada (1948) and to Australia and New Zealand (1956).²

On 24 June 2010 the NSA and the UK’s GCHQ declassified and published the text of the UKUSA Agreement together with documents from 1940–1956, appendices and later amendments.²