Bougainville was not an ‘unnecessary’ operation; it was more than just ‘mopping up’. The campaign would not change the outcome of the war nor help it end any sooner. But the Bougainville campaign needed to be fought in order to release Australian manpower for future operations against Japan and to allow for the release of servicemen for employment on the home front. Apart from a very select few who knew about the atomic bomb, virtually everyone else, Australian commanders and politicians included, expected the war against Japan would continue at least until 1946. Had the Australians not undertaken a controlled offensive against the Japanese, II Corps could have remained on Bougainville indefinitely. No one knew that the war was to end suddenly in August 1945. Fighting an aggressive campaign on Bougainville also fulfilled the government's long-standing political and strategic agenda of having Australian forces actively involved in the liberation of Australian territory.

The campaign itself was conducted with brutal skill and efficiency. From the very outset, the ultimate Australian objective was the ‘destruction’ of the Japanese. When the war came to an end, II Corps controlled about two-thirds of Bougainville: in the Central Sector, the Japanese were harassed and contained around Numa Numa; in the Northern Sector, although still aggressive, the Japanese fell back to the northernmost tip of the island; and in the Southern Sector preparations were underway for the final advance on Buin. This advance came at a price. Between October 1944 and August 1945, 516 Australians died on Bougainville and another 1572 were wounded. Most of these casualties were suffered by the infantry.