Intervention
When war broke out in Europe in 1914, President Woodrow Wilson
issued a Proclamation of Neutrality. However, maintaining
"neutrality in thought as well as action" proved impossible.
● Sinking of the Lusitania (1915): A British liner sunk by
German U-boats, killing 128 Americans. It shifted public
opinion against Germany.
● Unrestricted Submarine Warfare: Germany’s decision to
sink all ships (including merchant vessels) in the war zone
was the primary catalyst for U.S. entry.
● The Zimmermann Telegram (1917): A decoded message
from Germany to Mexico proposing an alliance against the
U.S. in exchange for the "lost territory" of Texas, New Mexico,
and Arizona.
● Wilson’s Idealism: Wilson asked Congress for a declaration
of war to make the world "safe for democracy."