New Guinea campaign
In the New Guinea campaign, the Eighteenth Army of Japan were left behind the Allied front, and although their position was of no strategic value, they still continued to fight. After United States forces crushed the 18th Army's counteroffensive in the Battle of Driniumor River, the Japanese were left alone. However, when the Australian Army took over the New Guinea campaign in the second half of 1944, they decided to do a thorough cleanup of the remaining Japanese forces.