 In April 1942 , Brigadier General Spencer Akin and his Australian counterpart at LHQ , Major General Colin Simpson , agreed to pool their resources and establish a combined intelligence organisation , known as the Central Bureau . The Australian , British , and US Armies , as well as the RAAF and the RAN all supplied personnel for this formation , which worked on codebreaking and decrypting Japanese message traffic . This Magic and Ultra intelligence was vitally important to operations in SWPA . 
