 Complete the following phrase:  In December 1941, due to concerns about a Japanese invasion, the Dutch requested that Australian forces be sent to both Koepang and Ambon under provisions that had been agreed to in a conference at Singapore earlier in the year. That plan, entitled Plans for the employment of naval and air forces of the associated powers in the eastern theatre in the event of war with Japan Plenaps, had already resulted in the disposition of forces, including some U.S. fleet movements, as early as November 1941. Initially, Australian plans were to send forces only to Koepang with the resulting order to embark the force at Darwin, designated Sparrow, on 7 December 1941 using the transport and the armed cruiser HMAS Westralia, which were available in the port. The decision to exclude Ambon was quickly changed with 1,090 troops designated Gull Force sent to 