Political map of Australia, New Zealand & the Southwest Pacific 14 January 1943 (Battle of Timor): After the Japanese attack on Pearl Harbor, the Australians and Dutch took over the weakly-defended Portuguese colony in eastern Timor. While most of Timor fell to Japan in February 1942, the mostly-Australian Allied forces continued to hold out in eastern Timor, fighting a guerrilla war against the Japanese until early 1943 (Battle of Timor).