Why the U.S. Entered World War I Against Germany

The U.S. declared war on Germany April 6, 1917, after neutrality since 1914. Key factors:

1. Unrestricted Submarine Warfare

Germany resumed sinking merchant and passenger ships without warning (e.g., Lusitania, 1915), killing Americans and causing outrage.

2. Zimmermann Telegram

Intercepted German proposal to Mexico for military alliance, promising help reclaiming "lost territories" from the U.S. Seen as sovereignty violation.

3. Sabotage and Espionage

German covert ops in U.S. targeted ships, factories, infrastructure.

4. Propaganda and Public Sentiment

Allied propaganda and leaders (Wilson, Roosevelt) framed intervention as moral duty.

5. Economic Implications

Submarine warfare threatened U.S. trade with Allies and economic security.

6. Allied War Weariness

By 1917, Allies exhausted; U.S. entry boosted morale and hope for decisive victory.

7. Moral/Humanitarian Concerns

Perceived German atrocities in occupied territories spurred sense of obligation.

These factors collectively ended U.S. neutrality.