Description The Bougainville campaign (Operation Cherry Blossom) was fought by the Allies in the South Pacific during World War II to regain control of the island of Bougainville from the Japanese forces who had occupied it in 1942. During their occupation the Japanese constructed naval aircraft bases in the north, east, and south of the island; but none in the west. They developed a naval anchorage at Tonolei Harbor near Buin, their largest base, on the southern coastal plain of Bougainville. On the nearby Treasury and Shortland Islands they built airfields, naval bases and anchorages. These bases helped protect Rabaul, the major Japanese garrison and naval base in New Guinea, while allowing continued expansion to the south-east, down the Solomon Islands chain, to Guadalcanal.
The Allied campaign, which had two distinct phases, began on 1 November 1943 and ended on 21 August 1945, with the surrender of the Japanese.
Before the war, Bougainville had been administered as part of the Australian Territory of New Guinea, even though, geographically, Bougainville is part of the Solomon Islands chain. As a result, the campaign is referred to as part of both the New Guinea and the Solomon Islands campaigns.
The Battle of the Treasury Islands was a Second World War battle that took place between 27 October and 12 November 1943[2] on the Treasury Islands group; part of the Solomon Islands as part of the Pacific Theatre. The Allied invasion of the Japanese held island group intended to secure Mono and Stirling Islands so that a radar station could be constructed on the former and the latter be used as a staging area for an assault on Bougainville. The attack on the Treasury Islands would serve the long term allied strategy of isolating Bougainville and Rabaul and the elimination of the 24,000 strong garrison in the area.
The invasion, to be conducted primarily by the New Zealand Army, supported by American forces, was codenamed Operation Goodtime. The New Zealand 8th Infantry Brigade Group, assigned to the United States' I Marine Amphibious Corps, launched the invasion of the Treasury Islands at 06:06 hours on 27 October. 3,795 men landed in the assault wave with the remainder of the Allied force landing in four waves during the following 20 days. The operation was the first amphibious assault launched by New Zealand troops since the Battle of Gallipoli in 1915.
On 1 November the flag was raised over the ruins of Falamae, the islands' capital, and civil administration was restored. Eleven days later the islands were declared clear of Japanese forces; although Japanese holdouts were sighted in the jungles into January 1944.
The operation, in conjunction with Operation Blissful, served to divert the attention of the Japanese Seventeenth Army from the next major Allied target in the Solomon Islands campaign. The success of the operation also helped to improve the planning of subsequent landings in the Pacific.
