After the fall of Singapore, the Australian government and many Australians feared that Japan would invade the Australian mainland. Australia was ill-prepared to counter such an attack. The entire 8th Division, deployed to Malaya, Ambon, Timor and Rabaul, was lost or rendered ineffective as the Japanese rapidly advanced. The Royal Australian Air Force (RAAF) lacked modern aircraft and the Royal Australian Navy (RAN) was too small to counter the Imperial Japanese Navy. The RAAF and RAN were greatly expanded, though it took years for these services to build up to their peak strengths. The Militia was mobilised but, although a large force, it was inexperienced and lacked modern equipment. In response to the threat, the Government appealed to the United States for assistance, and the 6th and 7th Divisions of the Second Australian Imperial Force (2nd AIF) were brought back from the Middle East. British Prime Minister Winston Churchill attempted to divert them to Burma, but the Australian Prime Minister, John Curtin, refused to authorise this movement. As a compromise, two brigades of the 6th Division disembarked at Ceylon, where they formed part of the garrison until they returned to Australia in August 1942.