‘A Matter of Joint Decision’: The Origins of British Nuclear Retaliation Procedures and the Murphy–Dean Agreement of 1958

Abstract Formally concluded by the British prime minister, Harold Macmillan, and the US president, Dwight D. Eisenhower, in June 1958, the Murphy–Dean Agreement was an important aspect of the Anglo-American nuclear relationship during the Cold War but has not yet been the subject of any detailed historical scholarship. Updated and reaffirmed by a succession of prime ministers and presidents, the Agreement’s sensitive but now declassified contents outlined the consultation procedures that would have to be followed if ever a decision was to be taken to use US nuclear forces based in the United Kingdom, or British forces equipped with US nuclear warheads. Based on new documentary evidence, this article offers the first analysis of the origins and background to the Murphy–Dean Agreement. It explains how the Agreement was rooted in the British government’s need to draw up its own initial set of nuclear retaliation procedures, which are outlined here for the first time; shows how the government was subjected to parliamentary pressure to conclude an agreement on consultation with the Americans; and argues that the eventual Agreement was highly significant in revealing the nature of the UK’s purported nuclear ‘independence’ in the late 1950s.