On 15 September 1939 Menzies announced the formation of the Second Australian Imperial Force (AIF). This expeditionary force initially consisted of 20,000 men organised into an infantry division (the 6th Division) and auxiliary units. The AIF was institutionally separate from the CMF, which was legally restricted to service in Australia and its external territories, and was formed by raising new units rather than transferring CMF units. On 15 November, Menzies announced the reintroduction of conscription for home-defence service, effective 1 January 1940. Recruitment for the AIF was initially slow, but one in six men of military age had enlisted by March 1940, and a huge surge of volunteers came forward after the fall of France in June 1940. Men volunteered for the AIF for a range of reasons, with the most common being a sense of duty to defend Australia and the British Empire. In early 1940, each of the services introduced regulations which prohibited the enlistment of people not "substantially of European origin"; while these regulations were strictly enforced by the RAN and Army, the RAAF continued to accept small numbers of non-European Australians.