2nd Australian Imperial Force

At the outbreak of the Second World War in September 1939 Australia's Army was predominantly a part-time force that was limited by the Defence Act to service in Australian territory. In order to support Britain in the war in Europe the Australian Government announced, on 15 September, the formation of a 'special force' of 20,000 men for service 'at home or abroad as circumstances permit'. Drawing on the traditions of the Australian force that had served in the First World War, the new force soon became known as the Second AIF. It was raised in isolation from the existing military structure and had its own conditions of service, unit establishments and seniority lists. Up until 1942, its commander, General Sir Thomas Blamey, answered directly to the Minister for the Army and not the Military Board. Five Second AIF Divisions were eventually raised - the 6th, 7th, 8th and 9th Infantry Divisions, and the 1st Armoured Division.

The differences between the AIF and the existing home-based militia force caused numerous administrative and strategic difficulties and there was considerable friction between the members of the two forces. The material differences between the two were progressively removed, a process accelerated by the entry of Japan into the war, but ill-feeling persisted in some quarters until the end of the war. In order to preserve the strength of the militia for home defence, in June 1940 its members were prevented from joining the AIF. In February 1942 regulations were changed to allow members of the militia to volunteer for service with the AIF, which meant being able to be sent anywhere in the world, but they would stay with their existing units. If 65 per cent of the establishment strength, or 75 per cent of the actual strength, of a unit volunteered for the AIF, that unit then became an AIF unit.