Mobile Force. Due to the provisions of the Defence Act 1903 this force was raised as part of the Royal Australian Artillery, even though it consisted of a large number of infantry. Second World War When the Second World War broke out between Britain and Germany in September 1939, the Second Australian Imperial Force (2nd AIF) was formed, to fight in France. The AIF's main strength would consist of four divisions raised in 1939–1940: the 6th, 7th, 8th and 9th. Major General Thomas Blamey was appointed commander of the 2nd AIF. Compulsory military service was introduced: all men over 21 had to complete three months training with the Militia. However, to ensure home defences, Militia members were barred from joining the AIF. After the British Expeditionary Force (BEF) withdrew from France in the Dunkirk evacuation in the face of the German Blitzkrieg, the 6th, 7th and 9th Divisions, as I Corps, were sent to Egypt. From late 1940, the individual divisions faced Italian and German forces in the North African Campaign. The 6th Division then experienced many casualties in mainland Greece, and on Crete, and 3,000 of its personnel were taken prisoner in this campaign. The 7th Division formed the body of the successful Allied invasion of Vichy French-controlled Lebanon and Syria in 1941. The 9th Division and part of the 7th played a celebrated defensive role at the Siege of Tobruk. In 1941, a start was made on raising the 1st Armoured Division, as part of the AIF. As fears of war with Japan mounted, most of the 8th Division was sent to Singapore, to strengthen the British garrison; the remaining battalions were deployed in the islands to Australia's north, at Rabaul, Ambon and Timor. Following short but bloody campaigns in Malaya and the islands, virtually all of the 8th Division was lost when stronger Japanese forces swept through South East Asia, in early 1942. In the Battle of Singapore alone, more than 15,000 Australians were taken prisoner. The 6th and 7th Divisions were recalled to Australia, as the country faced the prospect of invasion. While Winston Churchill, the British Prime Minister, had requested that the two AIF divisions be sent to Burma, the Australian Prime Minister, John Curtin, turned down this request, though he did agree to land two brigades of the 6th Division in Ceylon where they formed part of the island's defences during the early months