When America Joined WWI and Became a Global Power | Military.com: When America entered World War I, a century ago this week, the European powers were bogged down in a grinding trench war that had killed millions and ravaged the European continent.
Swinging its industrial might and vast manpower behind France and Britain against Germany and its allies on April 6, 1917, the United States tipped the balance of the conflict and marked its own emergence as a global power.
"World War I was clearly the turning point for developing a new global role for the United States, ushering in a century of international engagement to promote democracy," said Jennifer Keene, a World War I expert at Chapman University in California.
