Departing the Mediterranean, Waller returned to Australia in August 1941 for service in the South West Pacific. On 24 October, he took command of the light cruiser HMAS "Perth", berthed in Sydney. "Perth" had also lately returned from action in the Mediterranean, where she had participated in the Greek, Cretan, and Syrian campaigns, and been damaged on two occasions by German bombers. Waller was reportedly "tired" and "quite a sick man" at this time, but nonetheless prepared "Perth" for action quickly. In January 1942, the ship was assigned to American-British-Dutch-Australian Command (ABDA) to help defend the Dutch East Indies. She set sail for the ABDA Area on 15 February, the day that Singapore surrendered.