Battle of Isurava


The Battle of Isurava, also sometimes referred to as the Battle of Isurava – Abuari or the Battle of Isuraba, took place between 26 and 31 August 1942. Forming part of the Kokoda Track campaign of the Second World War, the battle involved military forces from Australia, supported by the United States, fighting against Japanese troops from Major General Tomitaro Horii's South Seas Detachment, who had landed around Buna and Gona in Papua mid-July 1942, with the intent of capturing Port Moresby to the south, via the overland route.
Several small engagements were fought north of Kokoda, before the village itself became the scene of heavy fighting as the Australian Maroubra Force fought to delay the Japanese advance throughout late July and into early August. After further fighting around Deniki, the Australians withdrew to Isurava, where the Militia soldiers of Maroubra Force were reinforced by two Second Australian Imperial Force battalions of the veteran 21st Infantry Brigade under Brigadier Arnold Potts.
In what became the first major battle of the campaign, the two sides fought a heavy engagement around Isurava in late August, as four Australian infantry battalions attempted to fend off attacks by a similarly sized Japanese force. On the other side of Eora Creek, clashes were fought around Abuari, as a Japanese battalion attempted to outflank the Australians at Isurava from the west, and cut the track around Alola, while another Japanese battalion attempted to flank Isurava to the west. Subjected to a heavy Japanese artillery bombardment, and lacking their own with which to counter this indirect fire, the Australians defended for four days, before conducting a withdrawal in contact, falling back towards Templeton's Crossing, which was the scene of further fighting in early September 1942.
In the years following the battle, the fighting around Isurava has come to form a key part of the Australian narrative of the campaign. The Japanese were victorious in capturing Isurava, but Australian accounts in the early years after the war characterised the battle as a successful delaying action by a heavily outnumbered force, that inflicted more casualties than it sustained, highlighting the bravery of Australian troops in an epic and desperate action of national survival. In this regard, the Battle of Isurava has come to form a key part of the Anzac legend, although recent accounts have re-examined the battle. As the size of the Japanese force committed to the fighting has been re-evaluated, the magnitude of the Australian defensive feat has also been reinterpreted. Recent analysis, while acknowledging the individual bravery of both Australian and Japanese soldiers, highlights tactical deficiencies on both sides, and now characterises the battle as one in which Australian forces were able to withdraw largely due to tactical errors from the Japanese commanders.

Background

Geography

The Kokoda Track stretches for a distance of north from Owers' Corner on the southern coastal plain to the east of Port Moresby to the village of Kokoda, passing through what was referred to during the early war years as "the Gap". Kokoda sits in the northern foothills of the steep and formidable Owen Stanley Range that dominates the central land mass, separating the northern coast from the southern. In 1942, the steep terrain offered considerable challenges to military operations, and both the Japanese and Allies misunderstood its nature at the time of the early fighting in New Guinea. To the Japanese, who had learned of the Gap through vague explorer's accounts, it potentially offered a corridor from Buna through the Owen Stanleys along which they could launch a quick advance on Port Moresby.
Conversely, the Allies believed it was a narrow and largely impassable path that could be blocked and held with only limited resources. The terrain rises and falls with regularity, up to up and down over the full length of the track, markedly increasing the distance to be traversed, although there are several flat areas, particularly around Myola. The vegetation is largely dense jungle and the climate mostly hot and humid, although the higher parts are cold. Around Kokoda and the northern beaches, as the terrain lowers towards sea level, it consists mainly of thick kunai grass and swamps. Warm and wet, the coastal area is highly malarial.
Isurava sits in a clearing on the first main peak of the Owen Stanleys, on the southern route from Kokoda as the track rises towards its highest peak at Mount Bellamy. It is positioned to the south of Deniki and the north of Alola on a north–south ridgeline. A rest house was positioned about to the south, with a view of the Eora Valley. To its east, the high ground falls steeply towards the fast-flowing Eora Creek which sits at the bottom of a deep ravine. Isurava lay on a spur that jagged west from the Isurava ridgeline towards Eora Creek, and was bounded to the north and south by two small tributaries that cut the track.
To the west of Eora Creek on the other side of the steep ravine, opposite Isurava, was the village of Missima. It lay on the slope that rose towards the Abuari ridgeline, sitting astride a smaller parallel track that joined the main Kokoda Track after passing through Abuari and crossing Eora Creek via a log bridge near Alola. Overlooked by a ridge to the north, Isurava was ultimately unsuited to defensive operations. The ridge to its north offered the Japanese artillery, of which at that stage of the campaign they had a significant advantage, the ability to range their fire down on the Australian position.
The track to the east of Eora Creek and the track junction around Alola offered the Japanese an easy avenue of advance around the flank, towards the Australian rear. Nevertheless, it was chosen over the Isurava rest house position further south when the area was reconnoitred in mid-August by Major Allan Cameron, the brigade major of the 30th Infantry Brigade and temporary commander of the 39th Infantry Battalion.

Strategic situation

For both sides, Port Moresby was strategically important, offering a forward base from which to project further operations. Following the failure of a seaborne assault by the Japanese on Port Moresby resulting from the Battle of the Coral Sea in May 1942 and further losses during the Battle of Midway, it was planned to capture the town via an overland advance across the Owen Stanley Range along the Kokoda Track. On 21 July 1942, Japanese forces landed on the northern Papuan coast at Basbua, between Buna and Gona.
The advanced landing forces, consisting primarily of the Colonel Yosuke Yokoyama's 15th Independent Engineer Regiment, sailed from Rabaul and came ashore unchallenged as there were only a small number of Australians stationed in the area. Shortly afterwards a small advanced element, supported by part of the 1st Battalion, 144th Infantry Regiment, began moving south-west towards Oivi, mounted in motor vehicles and on bicycles. These troops were initially tasked with proving the route over the Owen Stanleys before the main body of the landing force, Major General Tomitaro Horii's South Seas Detachment, arrived.
Following the landing, several minor skirmishes took place around Awala and Giruwa between the forward elements of the Japanese landing force – Yokoyama Force – and small groups of Australian and Papuan forces primarily from the Papuan Infantry Battalion. Brushing these aside, the Japanese began advancing steadily towards their objective on the southern coast. Meanwhile, the Australians, who had deployed only limited forces north of Port Moresby, attempted to delay the Japanese along the track long enough to bring reinforcements forward. The Australian reinforcement effort was hampered initially due to a shortage of essential combat supplies of food and ammunition in the forward areas, as well as limited port facilities, which slowed the transfer of the experienced Second Australian Imperial Force troops that had been withdrawn from the Middle East to Australia earlier in the year.
As shipping and logistics resources became available in mid-August, the initial 2nd AIF troops moved to Port Moresby and Milne Bay, while US engineer and service units began arriving to conduct vital airfield and port development work, to help improve the effectiveness of Allied supply system. Nevertheless, a lack of supplies forward of Port Moresby continued to limit the ability of the Allies to concentrate troops along the Kokoda Track throughout much of the campaign, as the native carrier system was stretched and aerial resupply - a technique that was still developing - was less effective than initially envisaged.
Shortly afterwards, a bridge at Wairopi was destroyed by the withdrawing PIB troops who had been reinforced by a platoon of Australians from the 39th Infantry Battalion. There was a brief fire-fight on 24 July, before the Japanese began forcing a crossing of the Kumusi River in rubber assault boats supported by mortars and machine gun fire. In the days that followed, skirmishes were fought around Gorari and at Oivi, before the Australians and Papuans were forced back to Deniki. From there, a small force was sent north to Kokoda, with the intent of holding the village and its logistically important airfield.
Over the course of a fortnight, two important engagements were fought around Kokoda in late July and early August. This was followed by a short but sharp engagement around Deniki before the Australians withdrew towards Isurava on 14 August. In the short lull that followed, the Japanese began landing the main body of Horii's South Seas Detachment on the northern coast, while minor patrol actions resulted in several skirmishes north of Isurava.
Elsewhere, on 7 August 1942, US forces carried out an amphibious landing on Guadalcanal in the Solomon Islands, which caught the Japanese by surprise. To counter this, a large naval force was dispatched, as well as part of the 41st Infantry Regiment, which had been intended to join Horii's force but was diverted, as Japanese attention and resources turned towards the fighting against US forces in the Solomons. The engagements around Kokoda and the US landing at Guadalcanal caused General Harukichi Hyakutake, 17th Army commander in Rabaul, to re-consider the drive on Port Moresby. It was realised that more supplies would be needed and an amphibious landing around Milne Bay was planned for late August. By 16 August, the decision to capture Port Moresby was postponed until Milne Bay was captured and the situation on Guadalcanal was resolved. Consequently, on 28 August Horii's South Sea Detachment was ordered to position itself at a suitable location south of the Owen Stanleys to capture Port Moresby once the strategic situation elsewhere had been resolved in Japan's favour.