New Guinea campaign

The New Guinea campaign of the Pacific War lasted from January 1942 until the end of the war in August 1945. During the initial phase in early 1942, the Empire of Japan invaded the Territory of New Guinea on 23 January and Territory of Papua on 21 July and overran western New Guinea (part of the Netherlands East Indies) beginning on 29 March. During the second phase, lasting from late 1942 until the Japanese surrender, the Allies—consisting primarily of Australian forces—cleared the Japanese first from Papua, then New Guinea, and finally from the Dutch colony.

The campaign resulted in a crushing defeat and heavy losses for the Empire of Japan. As in most Pacific War campaigns, disease and starvation claimed more Japanese lives than enemy action. Most Japanese troops never even came into contact with Allied forces and were instead simply cut off and subjected to an effective blockade by Allied naval forces. Garrisons were effectively besieged and denied shipments of food and medical supplies, and as a result some claim that 97% of Japanese deaths in this campaign were from non-combat causes. According to John Laffin, the campaign "was arguably the most arduous fought by any Allied troops during World War II".