Answer:
It weakened their attitude because it reduced their massive offensive strategy
Step-by-step explanation:
During the world war the American troops joined up with the Allied forces to defeat Germany in the war, the arrival of American troops weekended the attitude of the Germans because the American troops helped the allied forces repel most of the German offensives and also driving them out of already conquered territories.
American troops were very large in number and the Germans attitude of massive offensive reduced due to the presence of extra troops in support of the allied forces.