In the autumn of 1918, Sadleir-Jackson was rewarded for his war service with the presentation of the Legion d'honneur and the Croix de Guerre with Star. The following year he was made a Companion of the Order of the Bath. Despite these accolades, Sadleir-Jackson volunteered again in late 1918 to command the 2nd Brigade of the Russian Relief Force, a motley collection of units from the British Army, the Royal Navy, Australian volunteers, French and US troops and White Russians. This force was intended to hold the vital Northern ports of Arkhangelsk and Murmansk open for Allied cargo ships supplying the White Russian armies fighting in the region as part of the Allied intervention in the Russian Civil War.