Any investigation of the issue of imperial defence at the turn of the twentieth century must begin with the conflict in South Africa. In the first instance, the war crystallised anti-British feelings throughout Europe. The hostility of the great powers, with the exception of Japan and the United States, was clear in Britain and in the colonies. This was especially the case in Germany, where press attacks against British policy and the Empire in a wider sense were vehement. The spectre of European intervention in South Africa and a wider war (perceived dangers exacerbated by the shocking revelations of British military weakness of Black Week) were causes of significant political and public concern. Pre-existing, long-term feelings that the Empire was under siege were reinforced. The ‘blanket of public enthusiasm that had enveloped Britain's imperial enterprise during the 1890s’ was replaced by a drive for imperial consolidation and security. Men like Chamberlain embodied this sentiment; the Empire was the defining characteristic of Britain and things British, and its very existence depended on its being strong and unified. This atmosphere of fear partially accounts for the continuing failure of a Liberal vision in Britain, despite the efforts of such groups as the Fabian Society to use the war to advocate a revision of the imperial idea to include social and domestic reform. The conservative picture of Empire, even if it had transitioned from imperial celebration to imperial protection, was more dominant than ever during the war years, in the centre and in the colonies.

Under such circumstances many leading advocates of imperial unity saw both an opportunity and evidence in support of their arguments for more extensive intra-Empire connections. From South Australia, for example, Lord Tennyson, as Governor, wrote to Chamberlain in April 1900 that in his opinion ‘most prominent Australian statesmen’ saw the war as proof that the Empire should be ‘more firmly and formally federated than it is now’.