First, it passed the initiative to the enemy: he might decide he did not need to regain the lost ground, and so call the attacker’s bluff. Rawlinson could guarantee only that this would not occur where it was important for the enemy to regain the ground he had lost. Vimy Ridge, with its commanding height, was an example, as was the ring of hills to the east of Ypres: the town screened the Channel ports and the pivot of the British Expeditionary Force’s supply system, and the high ground guarded the Roulers railway junction and the hub of Germany’s transport network behind the western front.
