Assault Brigade: The 18th Infantry Brigade’s Development as an Assault Formation in the SWPA 1942-45

This study examines the evolution of the 18th Australian Infantry Brigade Group (Jungle) from its entry into the SWPA as a line infantry brigade to its culmination as the ‘assault brigade’ in the last amphibious assault of World War II at Balikpapan, Borneo. In the Allied campaigns of the South West Pacific Area (SWPA), the importance of the infantry brigade as a key combat formation became clear as the war progressed. From 1942 to 1945, the Australian infantry brigade was faced with the challenges of the SWPA and developed a brigade level ‘operational art’ that it used to adapt to the challenges of dense jungles, amphibious warfare, and overcome the onslaught of the Japanese Imperial Army and Navy. The complex terrain of the SWPA islands, which sometimes constrained, and at other times isolated the brigades from the parent division, also forced these formations to evolve or face devastating casualties. The Australian infantry brigades learned to integrate artillery, close air support, and naval gunfire to support infantry manoeuvre, vastly increasing their lethality. The 18th Infantry Brigade met the challenges of manoeuvre, administration, and military intelligence, which enabled the infantry brigade to conduct complex ground and amphibious operations across the SWPA.