Answer:
- Unrestricted submarine warfare
- Zimmerman Telegram
Explanation:
The United States entered World War I due to two major reasons: Germany's unrestricted submarine warfare and the Zimmerman Telegram.
Germany sank many American merchant ships around the British Isles in addition to the Lusitania, a British passenger ship. The sinking of the Lusitania resulted in a great loss of life.
The Zimmerman Telegram was a telegram from the German Foreign Office that proposed a military alliance between Germany and Mexico. In this telegram, Germany promised Mexico significant financial aid if they agreed to join the war as a German ally.
