The 18th Australian Infantry Brigade returned from the Buna and Sanananda campaigns a victorious but physically broken force. It had suffered more than 96 per cent casualties owing to a combination of weather, terrain, disease and the enemy, and would have to reconstruct the foundations of the brigade, built around a core of experienced veterans and the assimilation of motorised troops and replacement soldiers.1 The 18th Brigade would have to start building basic soldiering skills, the integration of jungle warfare lessons learnt, and the introduction of formal brigade leadership schools. This is also the period when the brigade undergoes a dramatic reorganisation under 7th Division’s establishment as a jungle division, which was outlined in chapter 1.

The subject of rubber supply to the German and American war industries is not a topic which thus far has materialised in the context of the historiography on Hitler’s declaration of war on the US. Both countries were dependent on imports of this crucial product – the Germans to a lesser extent once their newly created synthetic rubber industry began to produce the new ‘Buna’ rubber in large quantities by 1939. At the time, well over 90 % of the world’s natural rubber came from plantations in Southeast Asia, with Malaya and the Dutch East Indies providing the bulk. This was a subject Hitler was thoroughly familiar with, not the least because his Auswärtiges Amt liaison official Walther Hewel had worked as a plantation manager in SE-Asia for several years.

American attempts to develop a synthetic rubber industry were stymied by a lack of clear government policy and a persistent refusal to believe that the fall of the East Indies to a Japanese invasion would be more than transitory. Hitler tended to see this problem in a different light: any Japanese move on this region would force the Americans into prematurely moving the bulk of their half-ready armed forces to contest such a move, thus diverting US attention away from Europe for a considerable time.