Australian reinforcement was hampered by the logistical problems of supporting a force in isolated, mountainous, jungle terrain. There were few planes available for aerial resupply, and techniques for it were still primitive. Australian command considered that the Vickers machine gun and medium mortars were too heavy to carry and would be ineffective in the jungle terrain. Without artillery, mortars or medium machine guns, the Australians faced an opponent equipped with mountain guns and light howitzers that had been carried into the mountains and proved to be a decisive advantage. Australian forces were unprepared to conduct a campaign in the jungle environment of New Guinea. The lessons learned during the course of this campaign and the subsequent battle of Buna–Gona led to widespread changes in doctrine, training, equipment and structure, with a legacy that remains until the present day.