This volume considers change in British defence policy across more than a fifty year time period. There are four dangers with a project with such a scope. The first danger is that the book becomes overly descriptive, focusing upon narrative to the exclusion of analysis, becoming a far too narrow examination of one aspect of British and/or international politics. The second danger is that change is taken for granted, without there being any clear identification of the sources of change; again, this would encourage description over analysis, and a false presumption of 'inevitability' with hindsight, without understanding the complexity of the issue to the decision-makers of the time. In short, the danger of reinterpreting the past in terms of the present. The third danger is that unless the analysis is conceptually grounded it risks being quickly overtaken by events; that is, themes outlined here should have relevance beyond the time period selected for analysis. The fourth danger is that of too much generalisation, and insufficient attention to details, in the attempt to be comprehensive.