Zealanders began their pincer movement on 21 September, but the Japanese resisted so fiercely that it took until 5–6 October to bottle them up. On the night of 6–7 October, Rear Admiral Matsuji Ijuin led a naval force to take the 600 remaining ground troops off Vella Lavella. In response, a force of US destroyers was dispatched to intercept them. Each side lost a ship in the ensuing naval battle, but the Japanese were able to successfully complete their evacuation. As a result, General Barrowclough's men entered the evacuated area unopposed, concluding the New Georgia campaign. Kolombangara Kolombangara was evacuated between 28 September and 4 October after the U.S. forces completely ignored and bypassed it. The Japanese had stationed a large number of troops on the island and had heavily fortified it in expectation of mounting a stubborn defense, but MacArthur and Halsey's strategic plan was to only take lightly guarded beaches and islands and simply ignore the heavily defended islands. Aftermath Casualties during the campaign amounted to 1,195 US servicemen killed and 93 aircraft destroyed, while the Japanese lost 1,671 killed, and 358 aircraft destroyed. In addition, a total of 3,873 US troops were wounded. Casualties from disease were numerous, as were psychological casualties, with over 2,500 troops being diagnosed with "war neurosis" between 30 June and 30 September. The next stage of the Allied advance through the Solomons saw them land at Cape Torokina as part of efforts to secure Bougainville beginning in November; this campaign would last until the end of the war with Australian troops relieving US troops in late 1944. This was preceded by diversionary actions in the Treasury Islands by elements of the New Zealand 3rd Division, and by US Marines on Choiseul. Elsewhere, in New Guinea, commencing in late September, the Allies launched campaigns in the Markham Valley and on the Huon Peninsula as part of efforts to secure Lae and Finschhafen. In analyzing the campaign, historian Samuel Eliot Morison described it as "the most unintelligently waged land campaign of the Pacific war (with the possible exception of Okinawa)", and highlighted the decision to land at Zanana during operations to secure Munda as a mistake, suggesting that Laiana should have been chosen instead. Morison further criticizes the failed flanking move undertaken by Hester's troops to break the deadlock during the initial drive on Munda describing it as "perhaps the worst blunder in the