COLLAPSE OF JAPANESE IN THE CENTRAL SOLOMONS

The Allied capture of Munda on 5 August drove a wedge into the Japanese screen of defensive outposts to the south of Bougainville. Nine days after the Americans had taken the airfield, their construction battalions had repaired it and aircraft were able to operate from it. Although the Japanese air bases at Kahili and Ballale were only 120 miles away and the enemy still had considerable air forces in the Bismarcks-Solomons area, they made only two attempts to interfere with the construction work. During the previous few weeks in the air over New Georgia they had suffered losses out of all proportion to the successes they had gained, and from now on they husbanded their strength to protect their bases in Bougainville and New Britain.

On New Georgia the American land forces began a series of small mopping-up operations. Enemy forces holding outposts on the mainland and on the small islands off Munda Point were destroyed, and the whole New Georgia area was cleared by 3 September. The most important objectives in these operations were the enemy strongpoints at Bairoko Harbour, formerly a barge staging centre, and on Baanga Island off Munda Point, from which Japanese artillery had been able to shell Munda airfield.

The next Japanese-occupied area was Kolombangara Island, 10 miles from Munda, but as it was strongly held the American Command decided to bypass it and attack Vella Lavella, some 30 miles farther to the north-west. The United States forces landed there on 15 August and cleared the southern part of the island. On 18 September the American assault troops were relieved by 14 Brigade (Brigadier L. Potter) of 3 New Zealand Division, which completed the task of mopping up the remaining Japanese. By 9 October the remnants of the garrison had been either destroyed or evacuated. In the meantime an airfield was constructed at Barakoma in the south, from which aircraft were operating by 27 September.

The position of the Japanese at Kolombangara was now untenable. Vila airfield, only 10 miles from Munda, was shelled by American artillery early in September, and by 9 October air and naval bombardments had forced the Japanese to evacuate the island.

A month earlier they had abandoned their seaplane base at Rekata Bay on Santa Isabel. It had never been a great success on account of its proximity to Allied land-based aircraft. It was only page 196 140 miles from Henderson Field on Guadalcanal, and when the Allies moved into Munda, only 85 miles away, its position became hopeless.

During August the Japanese had made several naval attempts first to reinforce, and then to evacuate, garrisons in the central Solomons. On the night of 6–7 August an American destroyer squadron, under Commander Frederick Moosbrugger, defeated a force of four Japanese destroyers that was attempting to cover a convoy of reinforcements for Vila. Ten days later another American destroyer force, under Captain T. J. Ryan, Jr, attacked enemy reinforcements on their way to Vella Lavella. The escorting enemy destroyers were driven off, and then Ryan's ships turned on the troop-carrying barges. In the darkness it was impossible to be sure how many barges were destroyed, but it was considered unlikely that any escaped.

In early October the Japanese made several attempts to evacuate their men from Vella Lavella and Kolombangara, culminating in a major effort, heavily escorted by destroyers, on the night of 6–7 October. This was met and defeated by American destroyers, and the defeat put an end to the efforts to relieve the beleaguered garrisons. All the men who could be evacuated had been taken off or had drowned in the attempt.