In both world wars, individuals regarded as a threat to Australia’s war effort were incarcerated in internment camps. Ostensibly, an individual could be interned because of their birth or familial connections with enemy nations or because of their allegiance. In practice, however, internment was used much more broadly. Many people were interned with very little evidence of their threat to either the war effort or Australian society. Some ethnic groups, such as Japanese in World War II, were interned en masse. Internment, then, became a tool for social control and provided a mechanism for the removal of certain categories of people from Australian society.^[34]

In World War I, 6890 people were interned.^[35] At the peak of World War II, the number of civilian internees was closer to 12 000.^[36] In World War I, the policy stipulated that local authorities could intern ‘enemy subjects with whose conduct they were not satisfied’.^[37] Originally, the policy was concerned with people who had recently migrated to Australia. In 1915, however, it was broadened so that naturalised British subjects who were born in Germany or Austria could be interned, as well as people of ‘enemy descent’—that is, those who were born in Australia but whose father or grandfather was a subject of an enemy nation. Also interned were Australians of British descent who were thought to be ‘disaffected and disloyal’.^[38] They were singled out on account of their anti-war and anti-patriotic political persuasions and included radical pacifists, socialists, unionists and political and church leaders who campaigned against conscription.

In a time of war, when national security took priority over civil liberties, the people in the community who were not of British heritage became the objects of suspicion, surveillance, internment and, in many cases, more permanent exclusion. Australians of British descent who had worked for years alongside naturalised Europeans went on strike until the latter were sacked, and people reported on their neighbours. In some cases, even naturalisation was viewed with suspicion. Prime Minister, Billy Hughes, and other politicians in World War I argued that for the Germans naturalisation was only a ruse, ‘a cunningly and ruthlessly exploited cover’ that allowed them to continue their quest to undermine Australian society.^[39] Despite good relations in times of peace, the ethnic other remained an outsider in the Australian community. The internment experience, therefore, raised the question of whether people of non-British heritage could ever become Australians, and at what point they did belong to the Australian community.

Like Aboriginal reserves and quarantine stations, internment camps provided a mechanism for regulating the social boundaries of the Australian nation. While quarantine stations regulated the entry of people into the nation, Aboriginal reserves and enemy-alien internment camps regulated the membership of people who already resided in Australia. In much the same way, immigration detention centres regulate the entry of people into Australia and the membership of people who already live here. As a contemporary form of administrative detention, immigration detention centres raise the same questions of race, citizenship and belonging in the Australian nation-state as their institutional predecessors.