Zimmermann telegram
1917 World War I telegram from Germany to Mexico proposing an alliance
The Zimmermann telegram (or Zimmermann note or Zimmermann cable) was a secret diplomatic communication issued from the German Foreign Office on January 17, 1917, that proposed a military contract between the German Empire and Mexico if the United States entered World War I against Germany. With Germany's aid, Mexico would recover Texas, Arizona, and New Mexico. The telegram was intercepted by British intelligence.
Revelation of the contents enraged Americans, especially after German State Secretary for Foreign Affairs Arthur Zimmermann publicly admitted on March 3, 1917, that the telegram was genuine. It helped to generate support for the American declaration of war on Germany in April 1917.
The decryption has been described as the most significant intelligence triumph for Britain during World War I and it marked one of the earliest occasions on which a piece of signals intelligence influenced world events. The decryption was possible after the failure of the Niedermayer–Hentig Expedition to Afghanistan, when Wilhelm Wassmuss abandoned his codebook, which the Allies later recovered, and that allowed the British to decrypt the Zimmermann telegram.
Content
The message came in the form of a coded telegram dispatched by Arthur Zimmermann, the State Secretary of Foreign Affairs of the German Empire on January 17, 1917. The message was sent to the German ambassador to Mexico, Heinrich von Eckardt. Zimmermann sent the telegram in anticipation of the resumption of unrestricted submarine warfare by Germany on February 1, which the German government knew would almost certainly lead to war with the United States.
The public source identifies “Zimmermann telegram” as 1917 World War I telegram from Germany to Mexico proposing an alliance. This brief keeps that definition visible, then builds a research path around Zimmermann, telegram and World.
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This entry incorporates text from “Zimmermann telegram” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.