After his Allied forces had pushed the Japanese back in New Guinea, General Douglas MacArthur, Allied supreme commander in the South-West Pacific Area, was determined to continue the advance towards the Philippines.
This campaign has not always been recognised as one of significance to Australia since MacArthur chose to limit Australian involvement by excluding the Australian Army from his 'island hopping' operations. However, both the Royal Australian Navy and Royal Australian Air Force took part in the advance across Dutch New Guinea and the Netherlands East Indies.
While the Australians had been engaged in the Markham-Ramu Valleys and the Huon Peninsula campaigns in late 1943, American forces had conducted another series of landings on eastern New Britain and Hollandia in Dutch New Guinea. MacArthur planned further landings on islands in Dutch New Guinea and the Netherlands East Indies (now Indonesia). In what became known as 'island hopping', landings were made on well located but less heavily defended islands. This tactic of isolating and blockading rather than attacking, reduced Allied casualties.
The first landing in Dutch New Guinea was at Hollandia in April 1944. Australian warships were part of the Allied fleet that bombarded the landing area, and Australian LSIs (Landing Ships, Infantry) played their part by sending in landing craft carrying troops, tanks and equipment. Meanwhile, airmen flew top cover or landed to establish air-ground communications and to make captured airfields operational as quickly as possible. The Americans made good use of the Australian airfield construction squadrons.
The major American operations that followed were at Wakde-Sarmi and Biak Islands (May 1944) in Dutch New Guinea, then Noemfoor and Sansapor Islands in the Netherlands East Indies (July 1944), and finally Morotai and the Palau Islands also in the East Indies (September 1944). Although the more heavily defended islands were bypassed in this campaign, it was still costly. Almost 4000 Americans died during the capture of these islands and nearly 17,000 were wounded. A number of Australian airmen were also killed in these operations.
Australian warships and landing ships gained considerable experience in these amphibious operations. The success of subsequent Australian landings in Borneo in 1945 owed a great deal to the practical experience gained in Dutch New Guinea, the Netherlands East Indies and later the Philippines.
Airfield construction squadrons of the RAAF were some of the most experienced units in amphibious operations. At several locations, including Hollandia and Morotai, Australians were responsible for repairing captured airfields and building new ones. They landed shortly after the first waves of American troops, bringing ashore heavy equipment including bulldozers and graders to clear jungle and develop airfields. Australians also were responsible for bomb disposals and other support roles.
In the air, the RAAF contributed squadrons of Kittyhawk fighters, Beaufighter strike-fighters and Boston bombers which operated from some of the newly captured islands. One of the largest air bases was at Noemfoor Island, Dutch New Guinea from which the Australians flew many escort and ground attack missions sustaining mounting losses.
To the south, Australians based in the Northern Territory also supported the advance across the Netherlands East Indies. Long-range reconnaissance, bombing and strafing sorties were flown from bases around Darwin and to the south, such as Coomalie Creek. Catalina flying boats conducted minelaying sorties over a wide area against enemy shipping lanes and harbours. Most of the Australian squadrons based in the Northern Territory would later be deployed to the Netherlands East Indies to support operations against Borneo and also the Philippines.
This relatively little known 'island hopping' campaign across Dutch New Guinea and the Netherlands East Indies was one of the most successful of the Pacific war and made it possible for General MacArthur to honour his famous pledge to the Philippines: 'I shall return'.