The Battle of Talasea (6–9 March 1944) was fought in the Pacific theater of World War II between Japanese and Allied forces. Dubbed "Operation Appease" by the Allies, the battle was part of the wider Operations Dexterity and Cartwheel, and took place on the island of New Britain, Territory of New Guinea, in March 1944 as primarily US forces, with limited Australian support, carried out an amphibious landing to capture the Talasea area of the Willaumez Peninsula, as part of follow-up operations as the Japanese began withdrawing east towards Rabaul following heavy fighting around Cape Gloucester earlier in the year. The assault force consisted of a regimental combat team formed around the 5th Marines, which landed on the western coast of the Willaumez Peninsula, on the western side of a narrow isthmus near the Volupai Plantation. Following the initial landing, the Marines advanced east towards the emergency landing strip at Talasea on the opposite coast. Their advance south was stymied by a small group of Japanese defenders who prevented the US troops from advancing quickly enough to cut off the withdrawal of the Japanese force falling back from Cape Gloucester.

Prelude Background

Japanese forces captured the island of New Britain in February 1942 after overwhelming the small Australian garrison stationed around Rabaul. The Japanese subsequently built up a large garrison on the island, which became a lynchpin in the defensive barrier that they established following the failure of attempts to capture Port Moresby in late 1942. Actions around Cape Gloucester and Arawe – part of Operation Dexterity and the wider Operation Cartwheel – had been launched by the Allies to capture vital airfields and provide access through the sea passage between the straits separating New Britain from New Guinea, where during late 1943 the Allies had fought to secure the Huon Peninsula. In addition, the operations had sought to isolate the major Japanese base at Rabaul, as it had been decided that rather than destroying the base with a costly direct assault, a more prudent strategy would be to surround the base and therefore nullify it as a threat. The 1st Marine Division's operations to secure Cape Gloucester would continue until April under the command of Major General William H. Rupertus. However, by early February US commanders were confident that their forces would prevail in securing western New Britain and they began planning to expand towards the east, advancing towards Talasea – which offered a low grade airstrip and a potential base  – on the northern coast of the island, as part of actions to follow up the Japanese forces under Iwao Matsuda (Matsuda Force) who were withdrawing towards Cape Hoskins and Rabaul.

The operation to secure the Talasea area of the Willaumez Peninsula was dubbed "Operation Appease" by the US planners. It would require an amphibious landing on a beach, dubbed "Red Beach" near the Volupai Plantation, on the northeastern side of the neck of the peninsula, which was bounded by a dense swamp to the north and a steep cliff to the south. The terrain south of Red Beach rose to the northern part of Little Mount Worri, which was in turn overlooked by Big Mount Worri to the south, while to the east, Mount Schleuther extended towards the coast, overlooking several villages. It was intended that landing would be followed by an advance to the southeast, towards Bitokara and Talasea with a follow-up drive south, and a landing on Garua to secure the Garua Plantation.

Despite the limitations of the terrain on the flanks of the landing beach, to its front there were several redeeming features that offered tactical advantages for the troops undertaking the landing. The beach was situated along the narrowest part of the peninsula extending for a distance of east towards Garua Harbor, and had been identified as a likely landing zone by a former plantation owner, Flight Lieutenant Rodney Marshland, a Royal Australian Air Force officer; in this, it afforded a relatively flat and direct approach to the Marines' objectives, which were listed as the government buildings on the shore of Garua Harbor, the emergency landing ground at Talasea, and Garua Harbor. In addition, the beach was serviced by a dirt track that offered the potential for vehicle access.

Opposing forces The main US force assigned to the operation was Combat Team A, a task organised regimental combat team, which consisted primarily of the 1st and 2nd Battalions of the 5th Marines – under the command of Colonel Oliver P. Smith – supported by the 2nd Battalion, 11th Marines, a company from both the 1st and 17th Marines, and supporting elements including medical, armor, engineers, special weapons, ordnance, military police, and motor transport. Key supporting units included the 1st Medical Battalion, the 533rd Engineer Boat and Shore Regiment, the 592nd Engineer Boat and Shore Regiment, and the 1st Service Battalion. The US force consisted of a little more than 3,000 ground troops, with the total force being around 5,000; the majority of the landing craft were operated by the US Army engineers, with only a small number of US Navy vessels.

The Japanese defending Talasea consisted of the 1st Battalion, 54th Infantry Regiment, a company from the 2nd Battalion, 54th Infantry Regiment, and a battery from the 23rd Field Artillery Regiment. In addition, there was a platoon of machine guns and a platoon of 90 mm mortars. The force totaled 596 men, of which 430 were in the immediate Talasea area. These troops were drawn from Lieutenant General Yasushi Sakai’s 17th Division, and were grouped together as "Terunuma Force", under the command of Captain Kiyamatsu Terunuma. These troops were tasked with the defending the area in order to secure a withdrawal route for the troops from Matsuda Force that were withdrawing from Cape Gloucester, in western New Britain.

Battle

In the days prior to the assault, Royal Australian Air Force Bristol Beaufort aircraft flew numerous sorties from their base on Kiriwina softening up the defenses around the landing beach. On 3 March, the landing was preceded by a small reconnaissance patrol, consisting of an Australian officer – Marshland – an American and two indigenous scouts, which was put ashore by PT boat. After determining contacting friendly local inhabitants and ascertaining the strength and dispositions of the Japanese in the vicinity, the patrol had departed the peninsula and returned to Iboki around midnight on 3 March by PT boat. The following couple of days were used for battle preparation, after which the US force set off for the overnight journey on, embarking from the 5th Marines' base at the Iboki Plantation at 13:00 on 5 March 1944 upon a fleet of 60 assorted types of landing craft escorted by five PT boats. On board one of the landing craft were four medium tanks.

The following day, around first light, the landing was delayed almost half an hour as the fighter cover from the Fifth Air Force that had been assigned to support the landing failed to arrive; finally the order for the assault force to leave the line of departure was given by Smith despite the risks of proceeding without fighter cover. The initial assault force consisted of 500 marines from the 1st Battalion, 5th Marines. These troops were tasked with securing a bridgehead through which follow on troops from the 2nd Battalion, 5th Marines would pass as they pushed inland towards the Bitokara Mission. Due to the presence of a coral reef offshore, the initial assault had to be made by two companies from the 1st Battalion, 5th Marines aboard smaller tracked landing vehicles; these were lowered into the water from the larger tank landing craft, and as they made the run into the shore, they were provided covering machine gun fire from the tanks that were aboard one of the medium landing ships. This was answered by sporadic fire from the beach.

As the two assault companies came ashore, a small spotter plane on an observation mission flew overhead, dropping grenades in lieu of the promised air support from the 5th Air Force. According to U.S. Marine Corps historians, Hough and Shaw, citing Lieutenant Colonel Isamu Murayama's Southeast Area Operations Record, this impromptu air support was later described by the defenders as heavy. As the initial force pushed inland, several small scale clashes occurred, but the landing was largely unopposed. A beachhead was established about inland and patrols were sent out – on the right Company 'A' quickly met its objective, but on the left Company 'B' found the going a little harder due to swampy ground, which forced them to outflank it around the foothills of Lower Mount Worri where they encountered a small group of Japanese. To sea, the follow on waves were controlled by Lieutenant Colonel Robert Amory, in his own vessel, acting to ensure that the beach was not swamped by too many landing craft at the same time to ensure an orderly disembarkation as the 2nd Battalion followed up the 1st, moving through the beachhead towards Bitokara Mission. Nevertheless, the coral reefs slowed the boats coming in, forcing them to sail in single file, while the confines of landing beach made unloading slow and the requirement to manpack all equipment also added to the delays. Artillery landing on the water's edge suffered heavily from the Japanese mortars firing on the beach, while the medical staff on the beach also suffered heavily.

Regardless, the advanced elements of the 2nd Battalion, consisting of its Company 'E', began moving through the 1st Battalion around 11:00 hours, even though the 1st had yet to secure the edge of the plantation. Of the four Sherman medium tanks that had come ashore, one became stuck on the beach, while the other three moved forward to support Company 'E' as it advanced along the track leading towards the plantation. Almost immediately they had an effect, silencing a Japanese machine gun position; however, one tank was damaged by Japanese infantry who swarmed around it in an effort to place magnetic mines on it. One succeeded, although he died in the act, and the tank was temporarily put out of commission, drawing off to the side of the track. The other two tanks continued on, supporting the infantrymen along with 81 mm mortar fire as they advanced against the southwest corner of the plantation. There, the Americans gained an intelligence boon when they recovered a map of the local Japanese defenses from the body of a Japanese officer who had been killed in the fighting. Subsequently, two companies from the 2nd Battalion – 'E' and 'G' – gained momentum: 'G' moving on the right of 'E', traversing the mountain slopes while 'E' moved along the track. By nightfall on the end of the first day, the Marines dug in.