Ambiguity and Deterrence focuses on the role of competing strategic beliefs in the formulation of British nuclear strategy between 1945 and 1964. Based on recently released documents, it is argued that the British approach to nuclear weapons during this formative period was characterized byparadox and ambiguity. The paradox was that while there was a widespread consensus in political and military circles in favour of nuclear deterrence, there were constant disagreements over the requirements of an effective deterrent policy. These disagreements centred on six main questions: whetherdeterrence was best achieved through `punishment' or `denial'; whether deterrence necessitated nuclear superiority; whether preparations had to be made for a long war or a short war; what strategic implications followed from nuclear stalemate; whether limited nuclear wars could be fought withoutescalation to all-out nuclear war; and whether pre-emption was politically acceptable and militarily necessary. It is argued that the failure of successive governments to provide clear political direction on these issues meant that British nuclear strategy was more ambiguous and much less coherentthan is usually supposed.