Buna had been the main base for the Japanese on the north coast of Papua New Guinea. The military appreciation of the situation just before the battle suggested the difficulties the Allied force would face despite their material superiority:
Enemy is reduced in numbers, short of ammunition, food and supplies, whilst our Air Force and PT boats are preventing any large reinforcements or delivery of supplies. He is weak in artillery, has no tanks and has suffered a series of defeats. He has been attacked by our Air Force and artillery and has no adequate countermeasures.
He has had over six weeks to develop his defences and along all good approaches we can expect timber pill-boxes in depth which can only be located by actual contact. He is a determined defensive fighter and fights to the death, taking a heavy toll of attacking troops. He has used guns and Molotov cocktails in the jungle effectively against our tanks.
We have practically unchallenged air superiority, whilst our PT boats are effectively protecting our convoys of small craft to Oro Bay and forward to Hariko. Owing to the jungle it is not possible to derive adequate direct and close air support.
The Allies had a lot to learn about fighting in these conditions. Developing the tactics to make the best use of their tanks against the defensive bunkers was crucial. The final battle for Buna was over the 1st-2nd January when the base was taken by two attacks, one American, one Australian which converged on the base in a pincer movement.
Victory at Buna, only came with a pause in operations to allow proper planning, the reinforcement of the tanks, and the replacement of the tired and depleted 2/10th by the fresh 2/12th Battalion. They attacked on the morning of 1 January and, with the tanks and infantry co-operating closely, destroyed the bulk of the Japanese positions before nightfall. The destruction of isolated points of resistance continued the next day.
In the meantime, American troops had also been attacking east from Buna village and secured the Buna Government Station, and effected a junction with the force moving west form the old strip on 2 January.
The battle for Buna cost the Allied forces 2,870 casualties; the 18th Brigade had lost 863, including 306 killed. Close to 1,400 Japanese dead were countered, although their casualtiy toll was probably much higher when those killed or buried alive in destroyed bunkers are considered.