In light of developments in the Solomon Islands campaign, Japanese forces approaching Port Moresby were ordered to withdraw to and secure these bases on the northern coast.

Operations in Papua and New Guinea were severely hampered by terrain, vegetation, climate, disease and the lack of infrastructure; these imposed significant logistical limitations.

These factors were compounded by repeated demands from General Douglas MacArthur, Supreme Commander of Allied Forces in the Southwest Pacific Area, for a rapid conclusion to the battle.

In the closing stages of the battle, significant numbers of the defenders were withdrawn by sea or escaped overland toward the west and the Japanese base around Salamaua and Lae.

[4] US President Franklin Roosevelt ordered General Douglas MacArthur in the Philippines to formulate a Pacific defence plan with Australia in March 1942.

[11] Instead, in March 1942 the Japanese adopted a strategy of isolating Australia from the United States; planning to capture Port Moresby in the Territory of Papua and the Solomon Islands, Fiji, Samoa and New Caledonia.

The South Seas Detachment, under command of Major General Tomitarō Horii, advanced using the Kokoda Track to cross the rugged Owen Stanley Range.

[30][Note 6] These plans were rendered ineffectual by the rate of the Japanese withdrawal but it left the division well positioned to co-ordinate its advance on the beachheads with the Australians that were approaching from the southwest.

[40] The Japanese beachheads from which the Kokoda campaign was launched were located about three key positions along a 16-mile (25 km) stretch of the north coast of New Guinea: Gona to the west, Buna to the east and Sanananda–Giruwa in the centre.

[80][81] This eliminated the losses associated with air-dropping but the supply situation was consistently compromised by poor weather over the air route and a lack of transport aircraft.

[96] Many survivors of the Kokoda campaign congregated to the west, near the mouth of the Kumusi River and linked up with Japanese reinforcements that were landed there in early December.

[122] They made excellent use of terrain, which limited the tactical possibilities for attackers and consisted of hundreds of bunkers and machine gun emplacements developed in depth.

[142] Before the Allied forces arrived on the Buna–Gona coast, Richard K. Sutherland, then major general and MacArthur's chief of staff, had "glibly" referred to the Japanese coastal fortifications as "hasty field entrenchments".

[146][147][Note 23] Allied commanders in the field were unable to provide fire support capable of suppressing Japanese positions sufficient for infantry to close with and overwhelm them.

[153][154] The battle started on 16 November, when the Australian 7th Division crossed the Kumusi River,[155] about 40 miles (65 km) from the beachheads, in pursuit of the withdrawing Japanese forces.

[168] The Australian 7th Division continued to pressure the forward Japanese positions astride the Sanananda track without a decisive result, despite reinforcements and redeploying units that had been fighting at Gona.

As a result of the attack by 18 Aust Inf Bde on 12 Jan 43, it is now clear that the present position which has been held by the Jap since 20 Nov 42 consists of a series of perimeter localities in which there are numerous pill-boxes of the same type as those found in the Buna area.

Owing to the denseness of the undergrowth in the area of ops, these pill-boxes are only discovered at very short ranges (in all cases under 100 yards (90 m)) and it is therefore not possible to subject them to arty bombardment without withdrawing our own troops.

[224] Eichelberger set about restoring the flagging confidence of his men, conspicuously wearing the three stars on his collar among the front-line troops, ignoring the convention of removing insignia at the front so as to not attract the enemy.

[235] Australian war correspondent George Johnston wrote in Time magazine on 20 September 1943: "By a conservative count ... Bottcher and his twelve men ... killed more than 120 Japs.

[268] An attack was ordered for 29 November, even though the last of the Brigade's battalions was not due until the following day, possibly because of intelligence indicating the imminent arrival of Japanese reinforcements.

En route, on 11 December, it met stiff resistance from Japanese that had occupied a small cluster of huts and its advance toward Haddy's Village was slowed by a determined defence.

[289] There were 170 defenders buried after the attack but captured documents indicated a larger force had occupied the village and wounded had been evacuated prior to the final battle.

[299] The 2/10th Battalion, which had concentrated at the western end of the New Strip, achieved this on 22 December about 500 yards (500 m) west of the bridge, close to where the creek returned from making a sharp 'U' toward the cape.

[304] Despite the four tanks allocated to support the attack being destroyed by a concealed anti-aircraft gun at the outset,[305] the right flank was able to advance about 600 yards (500 m), having approached the fringe of the coconut plantation that extended around the coast from the western end of the Old Strip.

The impetus for the advance that day had been held by strongly contested positions which ultimately yielded to the tenacity of the attackers, who suffered heavily without the benefit of supporting tanks.

[342] On 20 December, the II/127th Battalion crossed the creek at the Coconut Grove under cover of smoke but the attack became confused and "fizzled out"; Urbana Force had made no progress in three days.

[345] An advance across the Government Gardens along an axis slightly north of east on 24 December was planned and the attack became a small unit action by companies without a clear distinction between battalions.

[400] In his book, Our Jungle Road to Tokyo, written in 1950, Eichelberger wrote, "Buna was ... bought at a substantial price in death, wounds, disease, despair, and human suffering.

"[401] Historian Stanley Falk agreed, writing that "the Papuan campaign was one of the costliest Allied victories of the Pacific war in terms of casualties per troops committed.