Operation Princeton

This was the US outline plan for the recapture of the Japanese-held Visayan islands and Mindanao island in the Philippine islands group, and of Borneo and the Netherlands East Indies (1943/44).

The basic concept was later developed via ‘Musketeer’ into the definitive ‘Montclair’ and ‘Oboe’ operations.

The 'Princeton' operation was planned by General Douglas MacArthur’s South-West Pacific Area as a joint US and Australian effort: Lieutenant General Robert L. Eichelberger’s US 8th Army was allocated the Visayan part of the operation, and Lieutenant General Sir Leslie Morshead’s Australian I Corps was allocated the Borneo part.

US planning had originally been based on the thinking that the elimination of the Japanese garrisons in the unliberated parts of the Philippine islands group would be undertaken by Filipino guerrilla forces supported by the re-formed Filipino army. On 6 February 1944, however, MacArthur ordered Eichelberger to mop up the Japanese forces in the Philippine islands group with his 8th Army, supported by Vice Admiral Thomas C. Kinkaid’s 7th Fleet. this culminated in the five 'Victor' operations. At the same time, the Australian I Corps was to retake Borneo and thereby facilitate the supply the US forces with oil for the invasion of Japan. Once Borneo had been liberated, the Australian I Corps was to form part of the Allied force to retake Java.