The United States entered World War I largely due to which factor?

The United States entered World War I largely due to which factor?

• A. Zimmerman Telegram
• B. Use of submarine warfare in the Atlantic
• C. Sinking of the Lusitania
• D. Assassination of Archduke Franz Ferdinand

Answer: (B)

Unrestricted submarine warfare by Germany directly threatened American lives and the right to ships’ safe passage on the Atlantic. When German U-boats began sinking merchant ships, including those carrying American passengers or goods, the United States faced a clear, immediate danger to its citizens and its economy. That made neutrality untenable and provided a concrete justification for asking Congress to declare war, because defending freedom of the seas and protecting neutrality required taking a stand against German aggression. The Lusitania sinking and the Zimmermann Telegram did influence public opinion and added urgency, but the decisive, defining factor driving entry was the submarine campaign that put American lives at risk and challenged the United States’ ability to remain neutral.

Unrestricted submarine warfare by Germany directly threatened American lives and the right to ships’ safe passage on the Atlantic. When German U-boats began sinking merchant ships, including those carrying American passengers or goods, the United States faced a clear, immediate danger to its citizens and its economy. That made neutrality untenable and provided a concrete justification for asking Congress to declare war, because defending freedom of the seas and protecting neutrality required taking a stand against German aggression.

The Lusitania sinking and the Zimmermann Telegram did influence public opinion and added urgency, but the decisive, defining factor driving entry was the submarine campaign that put American lives at risk and challenged the United States’ ability to remain neutral.