German stormtroopers in action. The 1918 Spring Offensive was a series of German attacks along the Western Front during World War I, beginning on March 21, 1918, which marked the deepest advances by either side since 1914. The Germans knew that their only chance of victory was to defeat the Allies before the overwhelming human and materiel resources of the United States could be deployed. The Germans were unable to move supplies and reinforcements fast enough to maintain their advance. By late April 1918, the danger of a German breakthrough had passed. Stormtroopers were specialist soldiers of the German Army in WWI. In the last years of the war, Stormtroopers were trained to fight with infiltration tactics, part of the Germans' new method of attack on enemy trenches. Men trained in these methods were known in Germany as Sturmmann and were formed into companies of Sturmtruppen. They were supported by rapid and accurate.