"We intend to begin on the first of February unrestricted submarine warfare. We shall endeavor in spite of this to keep the United States of America neutral. In the event of this not succeeding, we make Mexico a proposal of alliance on the following basis: make war together, make peace together, generous financial support and an understanding on our part that Mexico is to reconquer the lost territory in Texas, New Mexico, and Arizona." — Zimmermann Telegram (January 1917)
The telegram was decrypted and shared with Washington by
- Acheck_circle
British naval intelligence (Room 40)
- B
American Pinkerton detectives
- C
the French Deuxième Bureau
- D
the Russian Okhrana
Explanation
British codebreakers in Room 40 intercepted and decoded the cable, then carefully shared it with the U.S. while concealing how they had obtained German diplomatic traffic.