born Oct. 5, 1864, Marggrabowa, East Prussia
died June 6, 1940, Berlin, Ger.
German diplomat.
He became foreign minister of Germany in 1916 during World War I. With Germany's decision to resume unrestricted submarine warfare, he planned to reduce the possible U.S. intervention in Europe by embroiling it in war with Mexico. On Jan. 16, 1917, he sent a coded telegram to the German ambassador in Mexico, proposing a German-Mexican alliance that would allow Mexico to "reconquer her lost territory in Texas, New Mexico, and Arizona." It was intercepted and decoded by British naval intelligence, then published in the U.S. on March 1, causing public outrage. The "Zimmermann telegram" became a key factor in the U.S. declaration of war against Germany on April 6. Zimmermann was forced to resign in 1917.