With the approach of the Second World War, Australia's economic struggles with the Great Powers declined, and were replaced with military struggles with the Axis Powers. Australian secondary industry had been seen by the British Board of Trade as a direct threat to British exports to Australia. It was now seen by the ascendant British Admiralty, War, Air and Supply Departments as a positive asset to the defence of the British Empire. This provided a window of opportunity to consolidate Australian secondary industry and to expose it to the latest technologies.However, the production of munitions in Australia was disrupted by the Australian Armed Services attempting to take control of the organisation of industry for war. After nine months of confusion, the Department of Munitions was formed with the power to direct all industry without the interference of the Armed Services. Production of established munitions moved ahead with great speed, but the design of fighter aircraft and armoured fighting vehicles floundered because the Air Force and the Army were unable to define competently the weapons that they wanted in these areas. Eventually, Australian designed weapons did emerge in these areas, which were better than Japanese equivalents, but they were not always up to the standards set by the USA and Britain. One exception was the Thunderbolt Tank which turned out to be the most powerful Western Allied tank until the last weeks of the War in Europe.By early 1942, Australian industry had produced enough equipment and munitions to arm a force of eight divisions. These forces had better weapons than the Japanese, and in most cases, were more numerous than for Japanese divisions. The size of force that the Japanese calculated they would need to overcome the Australian divisions, was larger than the Japanese could supply without weakening the Chinese front, and was too large for Japanese shipping to transport without crippling Japanese industry through lack of imported materials. This was the real reason why the Japanese chose not to invade Australia. The situation in the air was no better for the Japanese because the Australian designed and manufactured Boomerang fighter aircraft was capable of matching the Japanese Zero fighter, when operating within the Australian East coast radar network. This was made up of radars designed and made in Australia. The US Navy victory at Midway, allowed secure communications to be established to Papua/New Guinea. This enabled the transfer of Australian military power from continental Australia. This saw the beginning of brutal jungle warfare between Japanese and Australian forces. But the Australians adapted more comprehensively. Australian science and industry started to make a completely new suite of equipments and munitions so that they could withstand the deleterious jungle conditions. This also included food and clothing, and medical supplies. In contrast, Japanese equipment, munitions, food and clothing suffered great loss from jungle organisms. The Australian advantages eventually allowed them to sweep the Japanese forces aside, with very low casualties, while inflicting heavy loss on the Japanese. Australian battlefield dominance was never acknowledged by General MacArthur, who insisted in describing their successes as Allied victories, while describing American successes as US victories. In fact, MacArthur's victories until well into 1944, were nearly all achieved by the very experienced Australians.MacArthur's dependence on the Australians went even further than this. Australia supplied enormous quantities of materials and equipments to the US forces in the South West Pacific. Most of the food consumed by the one million Americans in the South West Pacific came from Australia. President Truman pointed out that Australia supplied, per head of population, as much support as the much larger USA. No other Allied country came close to this level of support.