Internment camps were established for three reasons – to prevent residents from assisting Australia's enemies, to appease public opinion and to house overseas internees sent to Australia for the duration of the war. Unlike World War I, the initial aim of internment was to identify and intern those who posed a particular threat to the safety or defence of the country. As the war progressed, however, this policy changed and Japanese residents were interned en masse. In the later years of the war, Germans and Italians were also interned on the basis of nationality, particularly those living in the north of Australia. In all, just over 20 per cent of all Italians resident in Australia were interned.
During World War II, Australia interned about 7000 residents, including more than 1500 British nationals. A further 8000 people were sent to Australia to be interned after being detained overseas by Australia's allies. At its peak in 1942, more than 12,000 people were interned in Australia.