In early 1944, Walker was appointed second-in-command, alongside a new commanding officer, of the 4/8th Gurkha Rifles, who had suffered severely in the Arakan Campaign. In March the battalion was moved to the Imphal area where the Japanese had launched a major offensive and spent several months in hard fighting. In November he became the commanding officer, instigated a tough training regime and the battalion's motto – "Live Hard, Fight Hard, and when necessary Die Hard". Always a disciplinarian, he was a hard taskmaster and a totally professional soldier dedicated to hard training, and with his harsher characteristics balanced by integrity, generosity and warmth.