The Southwest pacific was one of two theatres in the pacific region during WWII. It included but was not limited to the Philippines, the Australian Territory of New Guinea (including the Bismarck Archipelago) and the western part of the Solomon Islands. Under the overall command of General Douglas MacArthur, US and Australian forces, along with smaller numbers of Dutch, Filipino and British soldiers, did battle against the Japanese in some of the most difficult terrain imaginable. As Allied strength grew on the land, sea and in the air, the tide of battle swung away from the Japanese. By the end of 1943, Allied air and naval superiority virtually assured an eventual victory.