The formation of the regiment following the end of the Second World War was fundamentally important to the post-war Australian Army, forming a key component of the first "permanent, professional army, available in peace and war for any task the government might direct". Prior to this time the Australian Army had been substantially a part-time militia with a permanent cadre. A major influence in the raising of the regiment was Australia's desire to secure a prominent role in the occupation of Japan and the eventual peace settlement. After some delays the 65th, 66th and 67th Battalions arrived in Japan's Hiroshima Prefecture in February 1946. Subsequent employment "involved activities designed to reinforce upon the Japanese the lesson of their defeat", in addition to guard duty, patrolling and training. In December 1948 the Australian component of the BCOF was reduced from a brigade to one understrength battalion, with the 1st and 2nd Battalions returning to Australia, while the 3rd Battalion remained in Japan.