Ritchie was not to remain at Sheerness long, however, as, after being promoted on 22 December 1939 to the acting rank of brigadier, he was made Brigadier-General Staff (BGS) to II Corps, commanded by Lieutenant-General Sir Alan Brooke. II Corps was then serving in France as part of the British Expeditionary Force (BEF). Ritchie seems to have immediately impressed Brooke, as on 3 January 1940 the latter wrote in his diary that "Ritchie, my new BGS, seems to be turning out well and should, I think, be good". When the so-called "Phoney War" came to an end in May 1940, which occurred when the German Army invaded France, Ritchie further impressed Brooke by controlling the corps HQ in a calm and confident manner, thus enabling Brooke to concentrate on running the battle on his corps' front. After being evacuated to England Ritchie was again requested by Brooke when the latter was appointed to command a new "Second BEF". Accompanying Brooke to France, he was again sent back to England, after Brooke realised that further efforts to fight the Germans were pointless and, in his words, "I sent Neil Ritchie off home this evening [16 June] as I did not feel that any useful purpose could be served by retaining him any longer". For his services in France and Belgium Ritchie was made a Commander of the Order of the British Empire on 11 July 1940, and was mentioned in despatches on 26 July.