By 1943, Japanese expansionary moves in the South West Pacific Area (SWPA) had ceased. Their advance in Papua New Guinea had been halted the previous year by the blocking action that Australian forces had fought along the Kokoda Track. Subsequent defeats at Milne Bay, Buna–Gona, Wau and on Guadalcanal had forced the Japanese on to the back foot. As a result of these victories, the Allies were able to seize the initiative in the region in mid-1943 and began making plans to continue to push the Japanese back in New Guinea.