As the outbreak of war was announced, police forces around Australia moved swiftly to ensure there were no concerns about security at home. German ‘enemy aliens’ - the same term as used in the previous war - were being rounded up. Those who were to be detained were identified from lists prepared before the announcement of the war.

Within hours, 257 people had been taken from their homes. Many more would follow.

Less than two weeks after his radio address, Menzies formed a War Cabinet. This collection of Government ministers would shape Australia’s decision-making in relation to the conflict.

While there were numerous similarities with World War I, there were also some differences that shaped the way Australia approached the issue of domestic security. In World War I, both civilian internees and prisoners of war - members of enemy armed forces captured during or after battle - were labelled Prisoners of War (POWs). In this war, international law demanded that a clear distinction be drawn between the two groups. While the military authorities charged with the care of both populations were obliged to treat them humanely, they would be subjected to different regimes of detention and held in separate places.

While the Government’s intention in 1939 was to limit internment to a select few, practices changed as the war progressed. Much like a generation earlier, enthusiasm to intern at home matched military fortunes abroad. After months of a Phoney War (when there was little fighting), hostilities exploded in April 1940, when German forces (the Wehrmacht) invaded Denmark and Norway. The following month, the Wehrmacht pushed through the Netherlands and Belgium; in June, France signed an armistice with Germany, and Italy entered the war on Hitler’s side. In Europe, the British seemed to stand alone in resisting the Nazis and, under their new Prime Minister, Winston Churchill, they braced for a battle for their very survival: it was a real and widely accepted prospect that Britain, too, would be invaded. On the other side of the world, rumours of the existence of a ‘fifth column’ - a term used to describe people who, it was thought, were seeking to undermine Australia’s war effort, and consisting largely of ‘enemy aliens’ with malicious intent - reached their peak.

The numbers of Germans interned grew, but they were no longer alone. Mussolini’s entry into the war, on 10 June 1940, triggered the arrests of Italians, using lists prepared in advance by intelligence authorities. In Queensland alone, 103 men were arrested within a day of Italy’s declaration of war, and many more would follow, including women and children. People who thought that being British subjects - whether by birth or naturalisation - would protect them from internment, were disappointed.