War was declared on Japan following the Bombing of Pearl Harbour in December 1941. Japan's pace of victories, and its conquest of Southeast Asia, extremely concerned Australian policymakers. Subsequently, the AIF was requested to return home, while the militia was called up. After the Fall of Singapore, and the consequent capture of the entire 8th Division as POWs, this haste was only increased. These events hastened the relief of the Rats of Tobruk, with the 6th and 7th Divisions immediately recalled to reinforce New Guinea. General conscription was reintroduced, though service was again limited to Australian territorial possessions. This limitation earned the Militia their epithet of "koalas", as they were a protected species that could not be exported or shot. Tensions primarily arose between the AIF and Militia due to the CMF's perceived inferior fighting ability, leading to the nickname of "chocos/chocolate soldiers".