page_title: Battle of the Green Islands
section_title: Operation
hierarchical_section_title: Battle of the Green Islands / Operation
caption_attribution_description: Français&#160;: Carte des opérations sur Nissan en février 1944
context_page_description: The Battle of the Green Islands or Operation Squarepeg was fought from 15 to 20 February 1944, between Imperial Japan and Allied forces from the New Zealand 3rd Division and the United States. Undertaken after landings to secure lodgments on New Britain and Bougainville, the main focus of the operation was the capture of Nissan Island, which was secured by New Zealand forces after only a short ground campaign. At only very limited cost in terms of casualties, the Allied operation resulted in the capture of several small atolls in the island chain, which were subsequently used to support air and naval operations focused on reducing the main Japanese base on Rabaul.
context_section_description: Under the command of Admiral William Halsey Jr., the invasion of the islands commenced on 15 February 1944, codenamed "Operation Squarepeg". Staging out of Vella Lavella and the Treasury Islands, Allied forces invaded several islands, including Nissan Island, and recaptured them from heavily outnumbered Japanese forces (estimated at around 120 to 150 strong). The main ground combat elements came from the three infantry battalions of the New Zealand 14th Brigade, of Major General Harold Barrowclough's 3rd New Zealand Division. The Japanese garrison consisted of 12 naval watchkeepers and about 80 army personnel from Hitoshi Imamura's Eighth Area Army, that had been landed by submarine in early February. This small force was reinforced further, reaching around 120.
  The infantry were transported aboard US Navy high-speed transport (APDs). These were escorted by a strong naval task force of destroyers, minesweepers and motor torpedo boats, under the command of Rear Admiral Theodore Wilkinson, while American LSTs landed the 3rd NZ Division Special Army Tank Squadron's Valentine tanks. Logistical support was provided by several US naval construction battalions (the 33rd, 37th and 93rd), as well as various other naval base and survey units. A US coastal artillery battalion was also landed to provide anti-aircraft defence, as were armoured, engineer, artillery, medical and other divisional logistic support units from the New Zealand 3rd Division.
  The fighting was brief, but sharp on land with heavier resistance in the air. Prior to the landing, as the assault force steamed towards the islands, a large group of Japanese aircraft were dispatched from Rabaul to attack the naval task force. The landing craft and transports escaped damage, but the cruiser St. Louis, which formed part of the southern covering force, was hit resulting in 23 killed and 28 wounded. Later, a group of dive bombers appeared over the landing craft as they were forming up to the west of the islands, but the Japanese aircraft were promptly dealt with by the escorting AirSols fighters from Cape Torokina, which quickly gained control of the air over Nissan Island. In all, the Japanese lost 12 aircraft. Apart from a near miss on LST-446, the landing proceeded quickly and smoothly, and after being crossloaded from the transports, the infantry were ferried ashore in LCIs and LCVPs, which proceeded to enter the lagoon to the south of Barahun Island, and disgorged their troops at several landing beaches around the Pokonian and Tangalan Plantations. In total 5,800 personnel were landed on 15 February, of which over 4,200 were New Zealanders.
  As the beachhead was established, there was only a brief resistance from several Japanese barges around Sirot Island, before a perimeter was established. Due to concerns about the possibility of counterattack from Rabaul, elaborate defensive measures were implemented. Patrols were sent out, and carrying parties began moving stores off the beaches further inland. A brigade headquarters was established around Tangalan Plantation, while Barrowclough's divisional headquarters was set up around Pokonian. The perimeter was held throughout the night. On 16 February, the New Zealand infantrymen began to push inland across the island. The 30th Infantry Battalion cleared the eastern side of the island around the Pokonian Plantation, while the 37th cleared the northern area of the island from Tangalan Plantation, the 35th pushed south. Each infantry battalion was supported by a troop of Valentine tanks, which provided close support and helped clear tracks through the jungle.
  A series of minor patrol actions took place in the 30th Battalion's area of responsibility, while a group of around 70 Japanese was encountered around a Catholic mission around the southern end of the island near Tanaheran, having become caught between patrols from both the 30th and 35th Battalions. This group of Japanese were overwhelmed over the course of several days by New Zealand infantry, supported by several tanks, at the cost of three killed and 11 wounded, while 
caption: Map of the landing, 15 February 1944
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