The Zimmermann Telegram (or Zimmermann Note; German: Zimmermann-Depesche; Spanish: Telegrama Zimmermann) was a coded telegram dispatched by the Foreign Secretary of the German Empire, Arthur Zimmermann, on January 16, 1917, to the German ambassador in Mexico, Heinrich von Eckardt, at the height of World War I. The Telegram's intention was to get Mexico to go to war against the United States, thereby diverting U.S. resources from aiding the Allies in Europe in their war against Germany.
The Telegram instructed the ambassador to approach the Mexican government with a proposal for a military alliance against the United States. He was to promise Mexico the opportunity to take back the land lost to the United States in the Mexican-American War, if Mexico helped Germany win the war. It was intercepted and decoded by the British, and its contents hastened the entry of the United States into World War I.