Pacific campaign continued
In December, 1943, MacArthur's forces invaded the southern tip of New Britain, Jap gunners shot the first wave of the 112th Cavalry to pieces and repulsed the attack. The main force did get ashore, but became bogged down in the swampy ground. On the north side of the island, the attack by the 1st Marine Division ran into similar difficulties, but on a larger scale. An overland advance on Rabaul was impossible. To overcome this obstacle the 126th infantry was shipped from Finschafen to land at Saidor and cut off the Japanese 20th Division who were defending Sio. Again the Japanese were forced to flee through rugged mountains, losing men to starvation and disease all along the trail of retreat.
After an Australian patrol found a complete cypher library for the 20th Division in a stream, Kenney convinced MacArthur that the Japs had abandoned Los Negros (the largest of the Admiralty Islands, 360 miles from Rabaul) and an invasion force of 1,000 officers and men of the 5th Cavalry Division landed on Los Negros on February 29th. The Japs were expecting an attack from the opposite direction and were caught by suprise when the 5th landed behind them. Although it was an accident, the good fortune of landing behind the enemy was put to good use and, after some vicious night fighting, the 5th won an impressive victory. Capture of the Admiralties allowed the allies to extend fighter cover beyond Wewak and the decision was taken to make an unprecedented 400 mile leap up the New Guinea coast to Hollandia. The value of the captured cyphers was to make the landing at Hollandia (Operation 'Reckless') a masterpiece of planning and 'Reckless' would prove to be the turning point in MacArthur's war against Japan. Through the cyphers it was learned that the planned landing at Hansa Bay would meet strong ground opposition and also the airbase at Hollandia was being 'beefed up' to support the land defense of Madang. It was also learned from the cyphers that the land defenses at Hollandia were minimal so 'Reckless' was planned and given the go ahead.
Hollandia was still beyond the range of land based fighters, so MacArthur was given three days of carrier fighter support and the invasion of Aitape was planned. By seizing Aitape, land based fighters could support the Hollandia landings and the carrier planes would be used to support the seizing of Aitape. 217 ships transported 80,000 men 1,000 miles to land in three separate areas on Aitape. With the island secure, Kenney was now allowed to crush the aircraft at Hollandia. The Japanese aircrews at Hollandia felt safe from allied aircraft and did not expect the flight of 60 B24's escorted by P38's with drop tanks that smashed the airfield at Hollandia on March 30th. Follow up raids demolished nearly all the serviceable Jap aircraft at Hollandia and never again did the Japs contest air superiority over New Guinea.
A deception plan kept the Japanese thinking that the next allied landing would be at Hansa Bay, and when the 24th and 41st Infantry Divisions waded ashore at Hollandia they were unoppossed. The same thing happened at Aitape, the Japanese Eighteenth Army was isolated in Eastern New Guinea and the Jap defences had been split.