The most important Dutch contribution was ships, especially merchant ships. The geography of the war made merchant ships a critical factor for both sides. The Japanese had to re-supply forces spread over a vast area, much of it thousands of kilometres from Japan and other supply sources. Some Allied supply lines were even longer - much of their military hardware came from the USA - and the Allies were using an island continent as a base from which to fight a war in islands and countries spread throughout a vast ocean. To win, the Allies needed many ships of all kinds, including the humblest of merchantmen.
Even today, aircraft could carry only the tip of the iceberg of military needs to a Pacific war. This was even more so sixty years ago with the tiny transport aircraft of the times. Merchant ships carried virtually everything. Passenger liners were pressed into service as troop ships; their speed and capacity becoming a key part of the Allied capability. Some liners become hospital ships. The Oranje, a Royal Netherlands Line ship, is one of the best remembered, carrying 32,461 sick and wounded Allied patients on over 40 voyages and operating from a number of Australian ports.
Indeed, almost everything that went to and from the Pacific War went by ship. In 1942, that most critical year, 19 of the 27 merchant ships that sailed to and from Australia were Dutch. Most were from KPM, the East Indies shipping line that had grown to more than 150 ships by the late 1930s. KPM had lost 79 ships during the Japanese invasion, and was now continuing operations from safer allied ports throughout the world.
Initially concentrated in Sydney where the company already had a base, KPM ships operated from most east coast ports, carrying some 100,000 Allied troops and over a million tons of cargo to the Pacific War during 1942-43. They remained a vital part of the Allied war effort until the end of the war.