Following his return from France on 31 May 1940, Adam was appointed General Officer Commanding-in-Chief Northern Command, responsible for the defence of the coastline from The Wash to the Scottish border.
Efter sin tilbagekomst fra Frankrig blev Adam udnævnt til øverstkommanderende for Northern Command, med ansvar for forsvaret af kystlinjen fra The Wash til den skotske grænse.