defence spending, in the context of increased Japanese aggression in China and Germany's aggression in Europe; however, there was a difference in opinion about how the defence spending should be allocated. The United Australia Party government emphasised co-operation with Britain in "a policy of imperial defence". The lynchpin of this was the British naval base at Singapore and the Royal Navy battle fleet "which, it was hoped, would use it in time of need". Defence spending in the inter-war years reflected this priority. In the period 1921–1936 totalled £40 million on the Royal Australian Navy, £20 million on the Australian Army and £6 million on the Royal Australian Air Force (established in 1921, the "youngest" of the three services). In 1939, the Navy, which included two heavy cruisers and four light cruisers, was the service best equipped for war. Fearing Japanese intentions in the Pacific, Menzies established independent embassies in Tokyo and Washington to receive independent advice about developments. Gavin Long argues that the Labor opposition urged greater national self-reliance through a buildup of manufacturing and more emphasis on the Army and RAAF, as Chief of the General Staff, John Lavarack also advocated. In November 1936, Labor leader John Curtin said "The dependence of Australia upon the competence, let alone the readiness, of British statesmen to send forces to our aid is too dangerous a hazard upon which to found Australia's defence policy." According to John Robertson, "some British leaders had also realised that their country could not fight Japan and Germany at the same time." But "this was never discussed candidly at...meeting(s) of Australian and British defence planners", such as the 1937 Imperial Conference. By September 1939 the Australian Army numbered 3,000 regulars. A recruiting campaign in late 1938, led by Major-General Thomas Blamey increased the reserve militia to almost 80,000. The first division raised for war was designated the 6th Division, of the 2nd AIF, there being 5 Militia Divisions on paper and a 1st AIF in the First World War. War On 3 September 1939, the Prime Minister, Robert Menzies, made a national radio broadcast: "My fellow Australians. It is my melancholy duty to inform you, officially, that, in consequence of the persistence by Germany in her invasion of Poland, Great Britain has declared war upon her, and that, as a result, Australia is also at war." Thus began Australia's involvement in the six-year global conflict. Australians