Germany understood the potential impact of America's entry into the war. By late 1917, following Russia's withdrawal from the war, Germany was able to concentrate all its military resources on the Western Front. The German high command still hoped to defeat the Allies on the Western Front before the United States could mobilize its full military potential.
In the so-called Spring Offensives of 1918, which began on 21 March 1918, the German army mounted a massive attack that was unlike any offensive that had been attempted to that point of the war. In March, Germany attacked along the Somme; in April, once more at Ypres, and in May, at Aisne. Using aircraft, tanks, and armoured trucks, the Germans succeeded in pushing back Allied lines towards Paris. As in 1914, German supply columns could not keep pace with the speed of the advancing troops. Soon, however, the shift in the balance of power began to have effect, and the Allies, now reinforced with American troops, finally halted the German offensives by mid-June.
The Spring Offensives were costly to attacker and defender alike. Germany had to endure the added burden of a crippling naval blockade that decreased food supplies and civilian morale. Unlike the now newly reinforced Allies, Germany could not replace its casualties.
In early August, the Allies pressed their advantage by launching an all-out assault of their own. Throughout the late summer and fall of 1918, Allied forces recaptured most of the territories that they had lost to the Germans earlier that year. The Canadian Corps was largely deployed in the Vimy area and, for the most part, was not involved in these operations. The major exceptions were the Canadian Cavalry Brigade and the Motor Machine Gun Brigade. The "Motors" were used extensively and with great effect, and at a high cost, to plug holes in the collapsing lines of the British 5th Army.