This thesis attempts to explore the influence that Duncan Sandys' experiences of the Second World War had on his policy preferences, and policy-making, in relation to British defence policy during his years in government. This is a significant period in British nuclear policy which began with thermonuclear weaponry being placed ostentatiously at the centre of British defence planning in the 1957 Defence White Paper, and ended with the British acquiring the latest American nuclear weapon technology as a consequence of the Polaris Sales Agreement. It also saw intense discussion of the nature and type of nuclear weaponry the British government sought to wield in the Cold War, with attempts to build indigenous land-based intercontinental ballistic missiles, and where British nuclear policy was discussed in extreme depth in government. The thesis explores this area by focusing on Duncan Sandys and examining his interaction with prominent aspects of the defence policy-making process. It argues that Sandys sought to navigate his way through this period of uncertainty by drawing heavily upon his experiences of the Second World War, and that this method of policy-making should be seen as a nuclear belief system unique to the individual, and therefore critical in understanding how British policy-makers approached the Cold War at the highest levels of government.