MacArthur, for his part, wanted to advance with American forces as soon as he could. In November 1942 he marched unprepared and undersupplied American troops on Buna. They were driven back to the beach, barely holding on to their landing zone. MacArthurs staff sent glowing communiqués claiming advance, and declared Buna secure. While the American public was happy with victory, the Australians were landed to actually take the objective. Buna was declared secure, but fighting continued. The Australian government was privately unhappy with the casualties and with the credit going to the Americans, who would not have succeeded without the Australians. Plus, the Australian public felt the primary goal should be developing a deense in case the Japanese invade Australia.
The Australians marched over the Owen Stanley mountain range to take Kokoda. MacArthur began landing forces in a series of protracted engagements that were slow progress up the back of New Guinea. While he was making progress, he wasnt advancing according to timetable and more and more of his supplies were going to Guadalcanal, where the War Department was realizing the major fight was.
New Guinea, for the Japanese, was their Vietnam. Entire units disappeared into he jungle, never to be heard from again. The Australians on the Owen Stanleys found cannibalism among the dead and dying Japanese they encountered. Imperial Army Air Forces were suffering huge casualties.
By 1944, MacArthur was landing with little opposition in the Morotai Islands. The American industrial might was beginning to tell, and he planned to use the Morotais to jump off into the Philippines.
New Guinea was some of the most difficult terrain in the South Pacific. Its size and lack cartography made it a difficult campaign for both sides.