Operation Battle of Arawe

The 'Battle of Arawe' was the core of the 'Director' (ii) operation, and was fought between Allied and Japanese forces on the south-western coast of New Britain island (15 December 1943/24 February 1944).

The battle formed part of the Allied 'Cartwheel' strategic undertaking, and was conceived as a diversion before a larger 'Backhander' landing at Cape Gloucester late in December 1943. The Japanese military was expecting an Allied offensive in the western part of New Britain, on the north-eastern side of the Vitiaz Strait from New Guinea, and was in the process of reinforcing the region at the time of the Allied landing at Arawe, which the Allies secured after almost six weeks of intermittent fighting.

The initial Allied goals for the landing at Arawe included securing a base for US PT-boats and diverting Japanese forces from Cape Gloucester. The PT-boat base was subsequently deemed unnecessary and therefore was not created. Only a small Japanese force was stationed at Arawe at the time, although reinforcements were making their way to the area. The Allies' main landing on 15 December was successful, despite a failed subsidiary landing and problems in the co-ordination of the landing craft. The US forces quickly secured a beach-head and dug in. Japanese air units made large-scale raids against this beach-head in the days after the landing, and late in December Japanese army troops unsuccessfully counterattacked the US force. In the middle of January 1944 the US force, now reinforced with additional infantry and armour, launched a brief offensive that pushed the Japanese back. The Japanese forces withdrew from the Arawe area toward the end of February as part of a general retreat from western New Britain.

In July 1942, the US Joint Chiefs-of-Staff directed that the main objective of the Allied forces in the South Pacific Area and South-West Pacific Area commands was to capture the Japanese forces' most important base at Rabaul on the north-eastern tip of New Britain. From August 1942, US and Australian forces conducted a series of offensives in New Guinea and the Solomon islands group with the object of eliminating Japanese positions in the region and establishing air bases within striking range of Rabaul. The Japanese forces in the area mounted a strong resistance, but were unable to stop the Allied advance.

In June 1943, the Allies launched the 'Cartwheel' major offensive to take Rabaul. During the next five months, Australian and US forces under the overall command of General Douglas MacArthur advanced along the north coast of eastern New Guinea, capturing the town of Lae and the Huon peninsula. US forces under the command of Admiral William Halsey simultaneously advanced through the Solomon islands group from Guadalcanal, and established an air base on Bougainville island during November. In June, the Joint Chiefs-of-Staff decided that it was unnecessary to capture Rabaul as the Japanese base there could be more effectively neutralised by blockade and aerial bombardment. MacArthur initially opposed this change in plans, but it was endorsed by the British and US Combined Chief-of-Staffs during the 'Quadrant' conference at Quebec during August.

Late in September 1943, the Japanese Imperial General Headquarters assessed the strategic situation in the South-West Pacific, and came to the conclusion that the Allies would in all probability attempt to break through the northern Solomon islands group and the Bismarck archipelago in the coming months on their way to Japan’s inner defensive perimeter in the western and central Pacific. Reinforcements were therefore despatched to strategic locations in the area in an attempt to slow the Allied advance. Strong forces were retained at Rabaul, however, as it was believed that the Allies would attempt to capture the town. At the time, Japanese positions in western New Britain were limited to airfields at Cape Gloucester on the island’s western tip and several small way stations which provided small boats travelling between Rabaul and New Guinea with shelter from Allied aerial attacks.

On 22 September 1943, MacArthur’s headquarters ordered Lieutenant General Walter C. Krueger’s 'Alamo' Force to secure western New Britain and the surrounding islands in an operation whose two goals were, firstly, to establish air and PT-boat bases to attack the Japanese forces at Rabaul and, secondly, to secure the Vitiaz and Dampier Straits between New Guinea and New Britain so that convoys could pass through them safely en route to the conduct of more landings along New Guinea’s north coast and beyond. To this end, the headquarters directed that both Cape Gloucester and Gasmata on New Britain’s southern coast were to be captured in an undertaking 'Dexterity'. Major General William H. Rupertus’s 1st Marine Division was selected for the Cape Gloucester operation, and the heavily reinforced 126th Regimental Combat Team of Major General William H. Gill’s 32nd Division was to attack Gasmata.

There was disagreement between senior Allied commanders about whether or not it was necessary to land forces in western New Britain. Lieutenant General George C. Kenney, commander of the Allied Air Forces, South-West Pacific Area, opposed the landings on the grounds that his forces did not need airfields at Cape Gloucester as the existing bases in New Guinea and surrounding islands were adequate to support the planned landings in the region. Vice Admiral Arthur S. Carpender, commander of both the 7th Fleet and the Allied Naval Forces, South-West Pacific Area, and Rear Admiral Daniel E. Barbey, commander of Task Force 76, supported the occupation of Cape Gloucester to secure both sides of the straits, but opposed the landing at Gasmata as it was too close to the Japanese air bases at Rabaul. The Gasmata operation was cancelled early in November in response to the concerns raised by Kenney and the US Navy as well as intelligence reports that the Japanese had reinforced their garrison there.

On 21 November, a conference was held between MacArthur’s headquarters, Kenney, Carpender and Barbey in Brisbane on the eastern coast of Australia. At this meeting it was decided to land a small force in the Arawe area in an operation whose three objects were the diversion of Japanese attention from Cape Gloucester, the provision of a PT-boat base, and the establishment of a defensive perimeter and to make contact with the marines once they had landed. It was intended that PT-boats operating from Arawe would disrupt Japanese barge traffic along the southern shore of New Britain and protect the Allied naval forces at Cape Gloucester from seaborne attack.

The Arawe area lies on the southern coast of New Britain about 100 miles (160 km) from the island’s western tip. Its main geographical feature is Cape Merkus, which ends in the L-shaped Arawe peninsula. Several small islands, called the Arawe islands, lie to the south-west of the Cape.

Late in 1943, the Arawe peninsula was covered by coconut trees which formed part of the Amalut Plantation, and the terrain inland from the peninsula and on its offshore islands was swampy. Most of the coast in the area has limestone cliffs. There was a small unused airstrip 4 miles (6.4 km) to the east of the neck of the Arawe peninsula, and a coastal trail leading eastward from Cape Merkus to the Pulie river, where it divided into tracks running inland and along the coast. The terrain to the west of the peninsula was a trackless region of swamp and jungle posing immense difficulty of movement for troops. Several of the beaches in the Arawe area were suitable for landing craft, the best of these being House Fireman, on the peninsula’s west coast, and one near the village of Umtingalu to the east of the peninsula’s base.

The 'Alamo' Force was responsible for the co-ordination of the planning for the invasion of western New Britain. The Arawe landing was scheduled for 15 December as this was the earliest date by which the air bases around Nadzab in New Guinea, which were needed to support the landing, could be made operational. This date also gave the landing force time to conduct essential training and rehearsal. As Arawe was believed to be only weakly defended, Krueger decided to use a force smaller than that which had been intended for the landing at Gasmata.This 'Director' Task Force was concentrated on Goodenough island, to the north of Papua’s south-eastern tip, where it was stripped of all equipment not needed for combat operations. Logistical plans called for the assault echelon to carry 30 days worth of general supplies and enough ammunition for three days of intensive combat. After the landing, holdings would be expanded to a 60-day supply of general supplies and six days worth of all categories of ammunition other than anti-aircraft ammunition, for which a 10-day supply was deemed necessary. The assault force and its supplies were to be carried in fast ships which could rapidly unload their cargoes.

The commander of the PT-boat force in the South-West Pacific Area was Commander Morton C. Mumma, who opposed the construction of extensive PT-boat facilities at Arawe as he had sufficient bases and as Japanese barges normally sailed along New Britain’s northern coast. Mumma took his concerns to Carpender and Barbey, who eventually agreed that he would not be required to establish a base he believed to be unnecessary. Instead, Mumms assigned six boats stationed at Dreger Harbor in New Guinea and Kiriwina island to operate along the southern coast of New Britain to the east of Arawe each night, and asked only for emergency refuelling facilities at Arawe.

The commander of the 'Director' Task Force was Brigadier General Julian W. Cunningham, who issued orders for the landing on 4 December. He directed that the task force would initially capture the Arawe peninsula and its surrounding islands, and establish an outpost on the trail leading to the Pulie river. The main body of the 'Director' Task Force was to land at House Fireman Beach on the Arawe peninsula at about dawn. Two troop-sized forces would have undertaken separate operations about an hour before the main landing: one troop was to capture Pitoe island to the peninsula’s south, as it was believed that the Japanese had established a radio station and a defensive position there, which commanded the entrance to Arawe Harbor; and the other troop was to land at Umtingalu and establish a blocking position on the coastal to the trail east of the peninsula. Once the beach-head had been secured, amphibious patrols would be conducted to the west of the peninsula in an attempt to make contact with the marines at Cape Gloucester. US Navy personnel on the planning staff were concerned about these subsidiary landings, as a night-time landing conducted at Lae in September had revealed considerable problems.

The 'Director' Task Force was based on the US Army’s 112th Cavalry Regimental Combat Team. This unit had arrived in the Pacific theatre during August 1942 but had not seen combat. It was dismounted and converted into an infantry unit in May 1943 and undertook the unopposed 'Chronicle' landing at Woodlark island, to the north-east of Papua’s southern tip, on 23 June. The 112th Cavalry was smaller and more lightly armed than US infantry regiments as it had only two battalion-sized squadrons compared to the standard infantry regiment’s three battalions. Moreover, the squadrons were smaller and more lightly equipped than their infantry equivalents. The 112th Regimental Combat Team’s support units were the 148th Field Artillery Battalion armed with M2A1 105-mm (4.13-in) howitzers and the 59th Engineer Company. The other combat units of the 'Director' Task Force were two batteries of the 470th Anti-aircraft Artillery Battalion (Automatic Weapons), most of the 236th Anti-aircraft Artillery Battalion (Searchlight), Company A of the US Marine Corps' 1st Amphibious Tractor Battalion and a detachment of the 26th Quartermaster War Dog Platoon. The 2/158th Infantry was held in reserve to reinforce the 'Director' Task Force if required. Several engineer, medical, ordnance and other support units were scheduled to arrive at Arawe after the landing had been completed. Cunningham requested a battery of 90-mm (3.54-in) anti-aircraft guns, but none were available. The US Navy’s Beach Party Number 1 would also be landed with the 'Director' Task Force and remain at Arawe until the beach-head was secure.

The 'Director' Task Force was supported by Allied naval and air units. The naval force was drawn from TF76 and comprised US destroyers Conyngham (Barbey’s flagship), Shaw, Drayton, Bagley, Reid, Smith, Lamson, Flusser and Mahan, and a transport group with the US destroyer transports Humphreys and Sands, the Australian infantry landing ship infantry Westralia, US dock landing ship Carter Hall, two patrol craft and two submarine chasers. The naval force also included a service group with three LSTs, three tugs and the US destroyer tender Rigel. US Army Air Forces and Royal Australian Air Force units operating under Major General Henry C. Morrow’s 5th Army Air Force would support the landing, but only limited air support was to be available after 15 December as the available aircraft were needed for strategic missions against Japanese bases.

Australian coastwatchers stationed on New Britain were reinforced during September and October 1943 to provide warning of air attacks from Rabaul bound for the Allied landing sites and to report on Japanese barge and troop movements. In addition to a coastwatching team already in place at Cape Orford near Wide Bay, other parties were sent to Cape Hoskins, Gasmata, Open Bay on the northern coast at the base of the Gazelle peninsula, the area south of Wide Bay, and the neck between Wide Bay and Open Bay. The Gasmata party was discovered by the Japanese en route to its destination and eliminated, but the other teams were in place by the end of October.

At the time of the Allied landing, the Arawe area was defended by only a small force, though reinforcements were on their way to the area. The Japanese force at Arawe comprised 120 soldiers and sailors organised in two temporary companies drawn from Lieutenant General Hidemitsu Nakano’s 51st Division. The reinforcing units were elements of Lieutenant General Yasushi Sakai’s 17th Division, which had been shipped from China to Rabaul during October 1943 to reinforce western New Britain ahead of the expected Allied invasion. The convoys carrying the division were attacked by US submarines and bombers, and suffered 1,173 casualties. The 1/81st Regiment was assigned to defend Cape Merkus. However, it did not depart Rabaul until December as it required reorganisation after suffering casualties when the ship transporting it from China was sunk. In addition, two of its companies, most of its heavy machine guns and all its 70-mm (2.76-in) howitzers were retained by General Hitoshi Imamura’s 8th Area Army at Rabaul, leaving the battalion with just its headquarters, two companies and one machine gun platoon. This battalion, which came under the command of Major Masamitsu Komori, was a four-day march from Arawe when the Allies landed. Oner company of the 54th Regiment, some engineers and detachments from other units were also assigned to the Arawe area. The ground forces at Arawe came under the overall command of Major General Iwao Matsuda, the headquarters of whose 65th Brigade was located near Cape Gloucester. The Japanese air units at Rabaul had been greatly weakened in the months before the 'Director' landing by prolonged Allied attacks and the transfer of Lieutenant General Einosuke Sudo’s 7th Air Division to western New Guinea. Nevertheless, the Imperial Japanese navy’s 11th Air Fleet, under the command of Vice Admiral Jinichi Kusaka, had 100 fighters and 50 bombers based at Rabaul at the time of the landing at Arawe.

The Allies possessed little intelligence on the terrain of western New Britain and also on the exact location of Japanese forces, so they flew extensive air reconnaissance sorties over the region, and small ground patrols were landed from PT-boats. A team from Special Service Unit No. 1 reconnoitred Arawe on the night of 9/10 December and concluded that there were few Japanese troops in the area, but the Japanese detected this party near the village of Umtingalu and strengthened their defenses there.

'Dexterity' was preceded by a major Allied air offensive which sought to neutralise the Japanese air units stationed at Rabaul. From 12 October until early November, the 5th Army Air Force frequently attacked the airfields around the town as well as ships in its harbor. Aircraft operating from US Navy aircraft carriers also attacked Rabaul on 5 and 11 November in support of the US Marine Corps' 'Cherryblossom' landing at Bougainville.

The Allied air forces began pre-invasion raids on western New Britain on 13 November. Few attacks were made on the Arawe area, however, as the Allies hoped to achieve tactical surprise for the landing and therefore wished not to alert the Japanese to their intentions. Instead, heavy attacks were made against Gasmata, Ring Ring Plantation and Lindenhafen Plantation on New Britain’s southern coast. The Arawe area was struck for the first time on 6 December and again on 8 December, encountering little opposition on either occasion. It was not until 14 December, the day before the landing, that heavy air attacks were undertaken against Arawe: 273 sorties were flown against targets on New Britain’s southern coast on that day. In addition to these air raids, TF74.2, comprising two Australian and two US destroyers shelled the Gasmata area during the night of 29/30 November.

The 'Director' Task Force was concentrated on Goodenough island early in December. The 112th Cavalry was notified that it had been selected for the Arawe operation on 24 November, and departed Woodlark island for the short passage to Goodenough island in two convoys that sailed on 30 and 31 November. All elements of the regiment were ashore on Goodenough island by 2 December, and a full-scale rehearsal of the landing was held at the island on 8 December, revealing problems with co-ordinating the various waves of boats and demonstrating that some of the force’s officers lacked sufficient amphibious warfare training. There was insufficient time for further training to rectify these problems, however. On Goodenough island, the troopers of the 112th Cavalry were issued with several types of infantry weapons new to them. Each of the regiment’s rifle squads received a Browning Automatic Rifle and a Thompson sub-machine gun, and a number of 2.36-in (60-mm) bazookas, rifle grenades and flamethrowers were also issued. The cavalrymen received little training on the use of these weapons, however, and therefore did not know how to make the best use of them.

The invasion force boarded its transport ships during the afternoon of 13 December. The convoy sailed at 00.00 and proceeded to Buna, on the east coast of Papua in New Guinea to rendezvous with most of the escorting destroyers. The complete invasion force made a feint to the north toward Finschhafen before turning toward Arawe after dusk on 14 December. The convoy was detected and reported by a Japanese aeroplane shortly before it anchored off Arawe at 03.30 on 15 December, and the 11th Air Fleet at Rabaul began to prepare aircraft to attack it.

Shortly after the assault convoy arrived off Arawe, Carter Hall launched LVT amphibious tractors and Westralia lowered landing craft, both operated by specialized US Marine and US Army units. The two large transports then departed for New Guinea at 05.00. The high-speed transports carrying Troops A and B of the 112th Cavalry’s 1st Squadron closed to within 1,000 yards (915 m) of Umtingalu and Pilelo island respectively, and unloaded the soldiers into rubber boats.

Troop A’s attempt to land at Umtingalu ended in failure. At about 05.25, the troop came under fire from machine guns, rifles and a 25-mm cannon as it was nearing the shore, and all but three of its 15 rubber boats were hold and sunk. Shaw, the destroyer assigned to support the landing, was unable to engage the Japanese positions until 05.42 as her crew initially could not determine if the soldiers in the water were in the ship’s line of fire. Once the destroyer had a clear shot, Shaw silenced the Japanese force with two salvos from her 5-in (127-mm) guns.The surviving cavalrymen were rescued by small boats and later landed at Beach House Fireman; casualties in this operation were 12 killed, four missing and 17 wounded.

Troop B’s landing on Pilelo Island was successful. The goal of this operation was to destroy a Japanese radio station believed to be located in the village of Paligmete on the island’s eastern coast. The troop was originally intended to come ashore near Paligmete, but the landing site was switched to the island’s west coast after Trop A had come under attack. After disembarking from their boats, the cavalrymen advanced to the east and came under fire from a small Japanese force stationed in two caves near the village of Winguru on the island’s northern coast. Ten cavalrymen were detached to contain the Japanese while the remainder of the troop continued to Paligmete. The village proved to be unoccupied, and did not contain the suspected radio station. The majority of Troop B then attacked Winguru, using bazookas and flamethrowers to destroy the Japanese positions. One US and seven Japanese soldiers were killed in the fighting. Personnel from the RAAF’s No. 335 Radar Station also landed on Pilelo island on 15 December and had established a radar station within 48 hours.

The 2nd Squadron, 112th Cavalry made the main landing on Beach House Fireman. The landing was delayed by a strong current and difficulties forming the LVTs into an assault formation, and the first wave hit the beach at 07.28 rather than the planned 06.30. Destroyers bombarded the beach with 1,800 5-in (127-mm) rounds between 06.10 and 06.25, and North American B-25 Mitchell twin-engined attack bombers strafed the area once the bombardment had come to an end, but the landing area was not under fire as the troops approached the beach. This allowed Japanese machine gunners to fire on the LVTs, but these guns were rapidly silenced by rockets fired from one submarine chaster and two DUKW amphibious trucks. The first wave of cavalrymen was fortunate to meet little opposition as there were further delays in landing the follow-up waves as a result of differences in the speeds of the two types of LVTs being used. While the four follow-up waves were scheduled to land at five-minute intervals after the first wave, the second landed 25 minutes after the initial force and the succeeding three waves landed simultaneously 15 minutes later. Within two hours of the landing, all the large Allied ships other than Barbey’s flagship had departed, and Conyngham remained in the area to rescue the survivors of the landing at Umtingalu before withdrawing later in the same day.

Once ashore, the cavalrymen rapidly secured the Arawe peninsula. A US patrol sent to the peninsula’s toe met only scattered resistance from Japanese rear guards. More than 20 Japanese in a cave on the peninsula’s eastern side were killed by members of Troop E and personnel from the squadron headquarters; the remaining Japanese units in the area retreated to the east. The 2nd Squadron reached the peninsula’s base at 14.30, where it began to prepare its main line of resistance. By the end of 15 December, more than 1,600 troops were ashore. The two companies of Japanese troops which had had been stationed at Arawe withdrew to the north-east, and took up positions at Didmop on the Pulie river about 8 miles (13 km) from the main line of resistance, and the naval unit defending Umtingalu retreated inland in disarray.

The Allied naval force off Arawe was subjected to a heavy air attack shortly after the landing. At 09.00, eight Aichi D3A 'Val' single-engined dive-bombers escorted by 56 Mitsubishi A6M5 Reisen 'Zero' single-engined fighters evaded the USAAF combat air patrol of 16 Lockheed P-38 Lightning twin-engine fighters. The Japanese force attacked the recently arrived first supply echelon, which comprised five LCTs and 14 LCMs, but these vessels managed to evade the bombs. The first wave of attackers suffered no losses, but at 11.15 four P-38 fighters shot down one A6M, and at 18.00 a force of 30 A6M fighters and 12 Mitsubishi G4M3 'Betty' and Mitsubishi Ki-21-II 'Sally' tein-engined medium bombers was driven off by four P-38 fighters. The Japanese lost two A6M fighters in the day’s air actions, but both pilots survived.

Although the US ground troops faced no opposition in the days immediately after the landing, naval convoys carrying reinforcements to the Arawe area were attacked on several occasions. The second supply echelon came under continuous air attack on 16 December, resulting in the loss of the small coastal transport APc-21 as well as damage to the submarine chaser SC-743, the auxiliary minesweeper YMS-50 and four LCTs. About 42 men on board these ships were killed or seriously wounded. Another reinforcement convoy was attacked three times by dive0bombers on 21 December as it unloaded at Arawe. Overall, at least 150 Japanese aircraft attacked Arawe during that day. Further air attacks took place on 26, 27 and 31 December. However, the Allied air forces were able to mount a successful defence of the Arawe area as the coastwatcher parties in New Britain provided 30- to 60-minute warnings of most incoming raids. Between 15 and 31 December, at least 24 Japanese bombers and 32 fighters were shot down near Arawe. During the same time period, Allied air units also raided airfields at Rabaul and Madang, the latter on New Guinea, which were believed to be the bases of the aircraft which had attacked Arawe. In air combat over Rabaul on 17, 19 and 23 December, 14 A6M fighters were shot down by Allied aircraft. The process of unloading ships at Arawe was hampered by air attacks and congestion on Beach House Fireman. The beach party contributed to these delays as it was inexperienced and too small. The resultant problems with unloading LCTs caused some to leave the area before discharging all their cargo.

Air attacks on Arawe declined after 1 January. As a result of the heavy losses they had suffered during attacks on Arawe and Cape Gloucester, and the damage caused by Allied raids on Rabaul, Japanese air units undertook only small-scale raids at night after this date. The Japanese naval fighter units based at Rabaul and nearby Kavieng on New Ireland island were also kept busy throughout January and February 1944 defending their bases from continuous Allied air attacks. Few raids were made against the Arawe area after 90-mm (3.54-in) anti-aircraft guns had been established there on 1 February. These weak attacks did nothing to disrupt the Allied convoys, and in the three weeks after the landing, 6,175 tons of supplies as well as 541 pieces of artillery and vehicles were transported to Arawe. On 20 February, the Japanese air units at Rabaul and Kavieng were permanently withdrawn to Truk, ending any significant aerial threat to Allied forces in New Britain.

Following the landing, the 59th Engineer Company constructed logistics facilities in the Arawe area. As a result of the period’s Japanese air raids, priority was given to the construction of a partially underground evacuation hospital, which was completed in January 1944. The underground hospital was replaced with a 120-bed above-ground facility in April 1944. Pilelo island was selected for the site of the PT-boat facilities, and a pier for refueling the boats and dispersed fuel storage bays were built. A 172-ft (52-m) pier was constructed at Beach House Fireman between 26 February and 22 April to accommodate small ships, and three LCT jetties were also built to the north of the beach. An airstrip measuring 920 vy 100 ft (280 by 30 m) was hurriedly built for artillery observation aircraft on 13 January, and this was later upgraded and surfaced with coral. The engineer company also constructed 5 miles (8.0 km) of all-weather roads in the Arawe region and provided the 'Director' Task Force with water via salt water distillation units on Pilelo island and wells dug on the mainland. These projects were continuously hampered by shortages of construction materials, but the engineers were able to complete them by improvising and making use of salvaged material.

The 112th Cavalry Regimental Combat Team strengthened its defensive positions during the week following the landing. As Troop A had lost all its weapons and other equipment during the landing attempt at Umtingalu, supplies were air-dropped into the beach-head during the afternoon of 16 December to re-equip the unit. The troop was also assigned 50 replacement personnel. Most of Troop B was also transferred from Pilelo island to the mainland in the days after the landing. The regiment improved its main line of defence by removing vegetation in order to create clear fields of vision and fire, establishing minefields and wire entanglements and laying a field telephone network. A reserve defensive line was also established closer to Cape Merkus, and patrols were conducted each day along the shores of the peninsula in search of Japanese personnel attempting to infiltrate the task force’s rear area. These patrols located and killed between 10 and 20 Japanese. In addition, the regiment established a network of observation posts throughout the Arawe area: these included positions in villages, key positions on the peninsula and on several offshore islands. Troop G was assigned to secure Umtingalu, and after doing so established a patrol base at the village as well as two observation posts along the track which connected it to the main line of resistance.

After being informed of the US landing, Sakai, the commander of the 17th Division, ordered that Arawe be urgently reinforced: however, Sakai did not believe that this would be the main Allied effort in western New Britain. The force under Komori’s command was ordered to make haste, and the 1/141st Regiment, stationed at Cape Bushing on the southern coast of New Britain about 40 miles (64 km) to the east of Arawe, was also directed to move by sea to counter the US landing. One of this battalion’s infantry companies remained at Cape Bushing, however. Komori was appointed the commander of all Japanese forces in the Arawe area, which were subsequently designated the 'Komori' Force. The 1/141st Regiment landed at the village of Omoi on the night of 18 December, and on the following day began an overland march to link with 'Komori' Force at Didmop. The battalion took eight days to cover the 7 miles (11 km) between Omoi and Didmop as it became lost on several occasions in the trackless jungle, and paused whenever contact with US forces seemed likely. The 'Komori' Force reached Didmop on 19 December and gathered the units which had retreated from Umtingalu into itself. On the basis of discussions with personnel who had witnessed the landing at Arawe, Komori mistakenly concluded that they had greatly overestimated the size of the Allied force. As a result, on 20 December he decided to launch a counter-offensive against the US positions.

After establishing its beach-head, the 'Director' Task Force undertook a series of reconnaissance patrols. Cunningham had been ordered to gather intelligence on Japanese forces in western New Britain, and on 17 December despatched a patrol of cavalrymen in two LCVPs to the west of Arawe to investigate the Itni river area. These landing craft encountered seven Japanese barges carrying part of the 1/141st Regiment near Cape Peiho, 20 miles (32 km) to the west of Arawe, on 18 December. After an exchange of fire the US soldiers abandoned their landing craft and returned to Arawe along the coast. Another patrol in LCVPs was engaged by Japanese barges near Umtingalu on 18 December but was able to return to Cape Merkus. Japanese barges were also sighted near Arawe on 23 December. Cunningham believed that a large Japanese force was heading for the beach-head, and contacted Krueger on 24 December to request that the 2/158th Infantry be despatched to reinforce his command. Krueger concurred and ordered that three of the battalion’s four companies be sent to Arawe. Company G of the 2/158th Infantry arrived on 27 December and the other two companies reached Arawe early in January.

After organising his force while waiting for the 1/141st Regiment, Komori began his advance toward Arawe on 24 December. He arrived at the airstrip to the north of Arawe during the early hours of the following day. During that morning, elements of the 'Komori' Force ambushed two platoon-sized US patrols traveling in trucks to the north-east of Umtingalu. The US units withdrew to the village and reinforced Troop G’s defensive position there. The US force drove off several Japanese attempts to move around Umtingalu during the day, and killed at least three Japanese. Cunningham believed that the force encountered around Umtingalu was the advance guard of a much larger Japanese force advancing from Gasmata, and withdrew the troopers stationed around the village to positions behind the main line of resistance. At 22.30 that night, 50 Japanese soldiers made a poorly co-ordinated attack on the main line of resistance. While they succeeded in overrunning some of the US positions, the Japanese were repulsed by fire from the 112th Cavalry’s 60-mm (2.36-in) mortars. The Americans lost one man killed and eight wounded, and estimated that the Japanese had suffered 12 casualties.

The Japanese offensive continued after the attack of 25 December. Two small attacks, each involving 15 men, were made against the eastern edge of the main line of resistance the nights of 26 and 27 December. These were also repulsed by the 112th Cavalry’s light mortars, and inflicted only a small number of casualties on the US force. On 28 December part of Troop B set out from the main line of resistance in an attempt to reach Umtingalu, but withdrew after encountering snipers and some light mortar fire. A platoon from Troop C also made an unsuccessful patrol from the western end of the main line of resistance in which it suffered six casualties from Japanese machine gun and rifle fire. On the same day, Komori dispatched a force of between 20 and 30 of his men to destroy the US mortar positions: the Japanese soldiers infiltrated the US positions by wading through swamps at the western end of the main line of resistance, but were detected before they could reach dry land. The 'Director' Task Force mounted a strong response, which included a counterattack by elements of three cavalry troops and a platoon of the 158th Infantry supported by mortars. The Japanese force suffered 17 casualties.

The 1/141st Regiment reached the Arawe area during the afternoon of 29 December, and undertook several small and unsuccessful attacks in early January 1944 before taking up positions about 400 to 500 yards (365 to 455 m) to the north of the main line of resistance. These positions comprised shallow trenches and foxholes which were difficult to see. While there were only about 100 Japanese soldiers in the area, they moved their six machine guns frequently, making them difficult targets for US mortars and artillery.

A US patrol located the Japanese defensive position on 1 January, and Troop B launched an attack later that morning, but was beaten off by heavy fire, suffering three men killed and 15 wounded. On 4 January, Troop G lost three men killed and 21 wounded in an unsuccessful attack on well-built Japanese positions. This operation had been conducted without artillery support in an attempt to surprise the Japanese, and also included a feint against Umtingalu involving several LCMs. More attacks on 6, 7 and 11 January failed to make any headway, but gave the cavalrymen experience in manoeuvring through the Japanese defensive positions. These US operations were undertaken on only a limited scale as Cunningham and the 112th Cavalry’s other senior officers believed that the unit had already achieved the goals of the landing at Arawe and wished to avoid unnecessary casualties.

On 6 January, Cunningham requested further reinforcement, including tanks, with which to tackle the Japanese defenses. Krueger approved this request and ordered Company F of the 158th Infantry and Company B of the US Marine Corps' 1st Tank Battalion to Arawe; the two units arrived on 10 and 12 January respectively. The marine tanks and two companies of the 158th Infantry subsequently practised tank-infantry co-operation from 13 to 15 January. During this period the 112th Cavalry continued to conduct patrols into Japanese-held areas, and by this time, the 'Komori' Force had incurred casualties of 65 or more men killed, 75 wounded and 14 missing in action as a result of its offensive actions as well as the attacks on it by the 'Director' Task Force. The Japanese were also suffering from severe supply shortages and an outbreak of dysentery.

The 'Director' Task Force launched its attack on 16 January. That morning, a squadron of Consolidated B-24 Liberator four-engined heavy bombers dropped 136 1,000-lb (454-kg) bombs on the Japanese defences, and 20 B-25 aircraft strafed the area. Following an intensive artillery and mortar barrage, the marine tank company, two companies of the 158th Infantry and Troop C of the 112th Cavalry attacked. The tanks led the advance, each followed by a group of infantrymen. The cavalry troop and three tanks were initially held in reserve, but were committed at 12.00 to mop up a Japanese position. The attack was successful, and had reached its objectives by 16.00. Cunningham then directed the force to withdraw to the main line of resistance. During this part of the operation, two marine tanks, which had become immobile, were destroyed to prevent the Japanese from using them as pillboxes. US engineers destroyed the Japanese defensive position on the next day. The 'Director' Task Force suffered 22 killed and 64 wounded in this operation and estimated that 139 Japanese had been killed.

Komori now pulled his remaining force back to defend the airstrip. As this was not an Allied objective, the Japanese were not subjected to further attacks by ground troops other than occasional patrol clashes and ambushes. As a result of the supply shortages, many of the Japanese soldiers fell sick. Attempts to bring supplies in by sea from Gasmata were disrupted by PT-boats and the force lacked enough porters to supply itself along overland trails. Komori concluded that his force was serving no purpose, and on 8 February informed his superiors that it faced destruction for lack of supplies. Even so, Komori was ordered to hold his positions.

The 1st Marine Division’s 'Backhander' landing at Cape Gloucester on 26 December was successful. The marines secured the airfields that were the main objective of the operation on 29 December in the face of only light Japanese opposition. Heavy fighting took place during the first two weeks of 1944 as the marines advanced from their initial beach-head to secure Borgen Bay. Little fighting took place once this area had been captured and the marines patrolled extensively in an attempt to locate the Japanese. On 16 February, a marine patrol from Cape Gloucester made contact with a US Army patrol from Arawe at the village of Gilnit. On 23 February, the remnants of the Japanese force at Cape Gloucester were ordered to withdraw to Rabaul. The 'Komori' Force was also directed to withdraw on 24 February as part of the general Japanese retreat from western New Britain. The Japanese immediately began to leave their positions, and headed to the north along inland trails to join other units. The US forces did not detect this withdrawal until 27 February, when an attack by the 2nd Squadron, 112th Cavalry and the marine tank company to clear the Arawe area of Japanese encountered no opposition. The 'Director' Task Force subsequently established a number of observation posts along the southern coast of New Britain and increased the distances covered by its reconnaissance patrols. Komori fell behind his unit, and was killed on 9 April near San Remo on New Britain’s northern coast when he, his executive officer and two enlisted men with whom they were travelling were ambushed by a patrol of the 2/5th Marines, which had landed in 'Appease' around Volupai and captured Talasea, on the Willaumez peninsula, early in March.

The Japanese force at Arawe suffered much heavier casualties than those of the Allies. The 'Director' Task Force’s total casualties between 15 December 1943 and the end of major fighting in the area were 118 men killed, 352 wounded, and four missing. Most of these casualties were men of the 112th Cavalry, which suffered 72 men killed, 142 wounded and four missing. Japanese casualties over this period were 304 men killed and three captured.

In the period immediately after the Japanese withdrawal, the 'Director' Task Force remained at Arawe. In line with standard practice, the 112th Cavalry continued to improve the defensive positions in the area. The regiment also undertook training, and some men were granted leave. A process of combat patrolling continued in the Arawe region in search of Japanese stragglers. Elements of the 40th Division began to arrive at Arawe in April 1944 to assume responsibility for garrisoning the area. The 112th Cavalry was informed that it was to be deployed in New Guinea early in June, and the 'Director' Task Force was disestablished at this time. The regiment sailed for the Aitape area of New Guinea on 8 June and next saw combat there during the 'Battle of the Driniumor River'.] The 40th Division maintained a garrison at Arawe until the Australian army’s 5th Division assumed responsibility for New Britain late in November 1944.