Remaining Australian Forces Evacuated from Portuguese Timor Leaving Japanese to Occupy the Island
By the end of 1942, the chances of the Allies re-taking Timor were remote, as there were now 12,000 Japanese troops on the island and the commandos were coming into increasing contact with the enemy.
The Australian chiefs of staff estimated that it would take at least three Allied divisions, with strong air and naval support to recapture the island. Indeed as the Japanese efforts to wear down the Australians and to separate them from their native support became more effective, the commandos had found their operations becoming increasingly untenable. Likewise, with the Australian Army fighting a number of costly battles against the Japanese beachheads around Buna in New Guinea, there were currently insufficient resources to continue operations in Timor. As such from early December Australian operations on Timor would be progressively wound down.
On 11–12 December, the remainder of the original Sparrow Force, except for a few officers, was evacuated with Portuguese civilians, by the Dutch destroyer HNLMS Tjerk Hiddes. Meanwhile, in the first week of January the decision was made to withdraw Lancer Force. On the night of 9–10 January 1943, the bulk of the 2/4th and 50 Portuguese were evacuated by the destroyer HMAS Arunta. A small intelligence team known as S Force was left behind, but its presence was soon detected by the Japanese. With the remnants of Lancer Force, S Force made its way to the eastern tip of Timor, where the Australian-British Z Special Unit was also operating. They were evacuated by the US Navy submarine USS Gudgeon on 10 February. 40 Australian commandos were killed during this phase of the fighting, while 1,500 Japanese were believed to have died.
Japan demanded the delivery of raw materials, most importantly OIL from Sumatra. The Dutch administration complied; yet in March 1942 the Japanese invaded, occupying most of the archipelago (southern New Guinea escaped Japanese occupation). The Dutch residents, in total 170,000, were INTERNED, a Japanese military administration established; the Japanese partitioned the archipelago in three zones, Sumatra, the Central and the Eastern Islands; many Indonesians found employment in the new administration. Dutch was replaced, as language of administration, education and jurisdiction, by Bahasa Indonesia and Japanese.