 On 17 April 1942 the Prime Minister of Australia , John Curtin , directed all Australian defence forces personnel to treat orders from MacArthur " as emanating from the Commonwealth Government " . The Army 's workshops and fixed fortifications , and the Royal Australian Air Force ( RAAF ) ' s logistical and training infrastructure , were not placed under SWPA . Having placed its troops at MacArthur 's disposal , the Australian government was adamant that it should be consulted on any alteration to the boundaries or command arrangements in SWPA . The government was particularly concerned that the Supreme Commander should not move troops outside Australia or Australian territory without its consent , as there were legal restrictions on where the Australian Militia could serve . The matter of changes in command first came up when Brett was replaced as Commander of Allied Air Forces by the Joint Chiefs of Staff . MacArthur and Curtin agreed that there would be no change to Blamey 's status , and that the government would be consulted about any other proposed changes . When Vice Admiral Herbert F. Leary was replaced a few months later , Curtin was consulted , and concurred with the change . 
