Answer:
Nationalism and imperialism encouraged each European nation to pursue its own interests and compete for power. ... The alliance system pulled one nation after another into the conflict.
Explanation:
Answer: The entry of the United States was the turning point of the war, because it made the eventual defeat of Germany possible. It had been foreseen in 1916 that if the United States went to war, the Allies' military effort against Germany would be upheld by U.S. supplies and by enormous extensions of credit.