Simpson deployed to the Middle East with them in late 1940, but shortly after arrival, he was seconded to the headquarters staff of the 7th Division, and later in the Syria–Lebanon campaign against the Vichy French in mid-1941. In early 1942, he returned to the 2/13th before being promoted to lieutenant colonel in March 1942 and taking command of the &lt;a href="2/17th%20Battalion%20%28Australia%29"&gt;2/17th Battalion&lt;/a&gt;; at this time he gained a reputation for his thorough training methods, and he subsequently led the battalion successfully through the Second Battle of El Alamein as the Allies launched a heavy offensive against the Germans and Italians in North Africa.