Guadalcanal was declared secured on 9 February 1943, but the Japanese continued air raids on the island for several months afterwards. The Japanese raids were staged out of their main air bases at Rabaul on New Britain, and used the smaller airfield at Munda Point on New Georgia further down the Solomon chain as a convenient refueling point to and from Guadalcanal. The airfield made New Georgia the painfully obvious next major target for Adm Halsey’s South Pacific command.

The Japanese pulled all of its remaining troops in the southern and central Solomons back to New Georgia, and the smaller nearby Rendova and Kolombangara islands, in anticipation of the American assault. The American invasions of the evacuated islands in the Central Solomons were unopposed, and in one case, was met by the local Australian coastwatcher with tea in celebration. Nevertheless, the Japanese troops were much more effective concentrated in the New Georgia archipelago. The defense of New Georgia was one of the few instances where the extreme rivalry between the Japanese Army and Navy did not affect combat operations. New Georgia was initially defended by Japanese Special Naval Landing Forces (marines) and reinforced significantly with Japanese troops of the 38th and 51st Divisions. Guadalcanal was the template, and the Tokyo Express began running supplies and troops to the island in anticipation of the American invasion.

Since the capture of Guadalcanal in February, the Munda airfield on New Georgia was subject to increased American air attack and naval bombardment in sort of a reverse to what the Japanese did to Guadalcanal. And with the same results: Munda Airfield wasn’t going to permanently cease operations because of bombardment any more than Henderson did ten months before. The invasion was so obvious the Japanese targeted the invasion fleet off Guadalcanal several times with air attack but took heavy losses in the process, with negligible effect on the fleet.

The initial landings in the New Georgia archipelago by US Marine Raiders occurred at the end of June 1943, and were tasked to capture an airfield at Segi, or survey a suitable location for one. The Raiders ended up coming to the assistance of a local coastwatcher, Donald Kennedy, whose exploits as an insurgent were legendary, if controversial, and it was his men who gave early warning of every Japanese air attack on Guadalcanal from Rabaul during the previous ten months. A Japanese battalion was ordered to shut him down once he was isolated on Segi Point.

The main landings for “Operation Toenails” occurred on 30 June. The invasion force was built around a composite force centered on the US Army 43rd Division and included US Marines, Marine Raiders, and the 1st Commando Fiji Guerrillas, an elite unit of volunteer Fijians under picked New Zealanders. The initial landings, on the island of Rendova, Wickham Anchorage, and Viru Harbor in preparation for the main landings on 3 July, were chaotic to say the least. The highly trained “Barracuda Scouts” of the US 172nd “Blackhawk” Infantry Regiment, the regiment tasked with seizing Rendova, landed on the wrong island. The main body landed in the correct spot and expected no resistance based on the information the scouts gave them the night before. Fortunately, there were only 250 Japanese defenders on the island and the 172nd overwhelmed them. It set a costly precedent for the 43rd that led them to underestimate the Japanese to their front, at great cost, for the rest of the battle. At Viru, the landing depended on a column of Marine Raiders from Segi to march overland and attack the Japanese from behind during the landings. However, the Marines grossly underestimated the amount of time they’d need to make the march through the thick broken jungle and didn’t arrive until the 2nd. All three of the initial objectives were eventually secured, but the terrain rendered them ineffective for their proposed roles in future operations. They were simply too far away, not in distance, but in time necessary to traverse the unforgiving jungle to the main objective of Munda Point. Miscalculating the effects of the terrain would prove to be the defining feature of the Battle for New Georgia.

The two other regiments landed in the south coast of New Georgia Island on 3 July and in the north on 5 July. The two landings were not mutually supporting and were intended to surprise and overwhelm the Japanese. Moreover, the southern landing didn’t land at the beach closest to Munda, Lainana beach, again in an attempt to surprise the Japanese, but at Zanana beach three miles further away from Munda. The two beachheads were expected to link up on 7 July for an assault on Munda airfield on the 8th, but the Japanese isolated both beachheads. Furthermore, the farther the Americans got from the invasion beaches, the more difficult the logistics situation became due to the near impossibility of hauling the supplies over the rough and narrow jungle track. The three miles to Lainana beach took almost ten days and nearly depleted the division.

On the night of 6 July, the northern invasion force bumbled into the Tokyo Express bringing Japanese reinforcements to New Georgia in the Kula Gulf. Both sides managed to land their troops, the Americans just before the contact and the Japanese just after. However, the American task force was savaged by a spread of Japanese “Long Lance” torpedoes, about the only remaining asymmetric advantage that the Japanese retained after the crucible that were the surface actions off Guadalcanal the autumn before. For the next two weeks, both invasion forces were isolated and attritted through a skillful Japanese defense. On 13 July the southern force captured Lainana beach which considerably shortened their supply line, but by then the damage was done.

The Tokyo Express continued to pour troops on to Kolombangara and New Georgia nightly and there was a very real threat that the American would be defeated in detail and thrown back into the sea. The Americans dug in but the Japanese seemed to be everywhere, with Japanese patrols attacking the lines and trail at will. The fresh Japanese troops would silently sneak into the exhausted American foxholes at night and slit the occupants’ throats. They called out individual commanders and reminded them they “weren’t in Louisiana anymore”, a reference to the training validation exercise the year before. The Japanese even managed to overrun the 43rd’s headquarters at Zanana beach.
The 43rd’s reports were bad but did not indicate disaster. They were reinforced by the 37th Infantry Division and only on a visit by the XIV Corps commander did the true situation emerge. Halsey’s Army Air Force commander happened to visit the island also, and being the ranking three star on the island immediately ordered the corps commander to stay and take charge. The he told Halsey that they’d need “at least another division”. Halsey sent three.

It wouldn’t have mattered had the Allied navies not secured the narrow waters and isolated New Georgia and Kolombangara. The US Navy again came off worse at the Battle off Kolombangara on 12 July, and it was up to air power and PT boats to stop the Tokyo Express for the next several weeks. The PT boats especially took serious casualties, including one boat cut in half by a Japanese destroyer – Its skipper was Lieutenant (junior grade) John F. Kennedy.

By early August, the tables were turned on the Japanese, and they were exhausted and weren’t getting the support they needed to continue. The US Navy finally caught the Tokyo Express by surprise in Vella Gulf on the night of 6-7 August which ended any hope of the Japanese continuing the fight for much longer. About the same time, the overwhelming number of Army and Marines on the island had slowly and painfully squeezed the Japanese Munda pocket. Sensing the inevitable, the Japanese evacuated New Georgia for Kolombangara on 20 August. The Americans would let them rot, and bypassed the island in September with the invasion of Vella LaVella. The Japanese stealthily evacuated Kolombangara in October.

Historian Samuel Elliot Morrison called the operations on New Georgia “the most unintelligently waged land campaign of the Pacific war”.