Zimmermann Telegram
The Zimmermann Telegram (or Zimmermann Note or Zimmermann Cable) was a secret diplomatic communication issued from the German Foreign Office in January 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.[1]
The decryption has been described as the most significant intelligence triumph for Britain during World War I[2] and it marked one of the earliest occasions on which a piece of signal intelligence influenced world events.[3]
History[edit]
Previous German efforts to promote war[edit]
Germany had long sought to incite a war between Mexico and the United States, which would have tied down American forces and slowed the export of American arms to the Allies.[7] The Germans had aided in arming Mexico, as shown by the 1914 Ypiranga incident.[8] German Naval Intelligence officer Franz von Rintelen had attempted to incite a war between Mexico and the United States in 1915, giving Victoriano Huerta $12 million for that purpose.[9] The German saboteur Lothar Witzke, who was based in Mexico City, claimed to be responsible for the March 1917 munitions explosion at the Mare Island Naval Shipyard in the San Francisco Bay Area,[10] and was possibly responsible for the July 1916 Black Tom explosion in New Jersey.
The failure of United States troops to capture Pancho Villa in 1916 and the movement of President Carranza in favor of Germany emboldened the Germans to send the Zimmermann note.[11]
The German provocations were partially successful. President Woodrow Wilson ordered the military invasion of Veracruz in 1914 in the context of the Ypiranga incident and against the advice of the British government.[12] War was prevented thanks to the Niagara Falls peace conference organized by the ABC nations, but the occupation was a decisive factor in Mexican neutrality in World War I.[13] Mexico refused to participate in the embargo against Germany and granted full guarantees to the German companies for keeping their operations open, specifically in Mexico City.[14]
Mexican President Venustiano Carranza assigned a military commission to assess the feasibility of the Mexican takeover of their former territories contemplated by Germany.[18] The generals concluded that such a war was unwinnable for the following reasons:
The Carranza government was recognized de jure by the United States on August 31, 1917, as a direct consequence of the Zimmermann Telegram to ensure Mexican neutrality during World War I.[20][21] After the military invasion of Veracruz in 1914, Mexico did not participate in any military excursion with the United States in World War I.[13] That ensured that Mexican neutrality was the best outcome that the United States could hope for even if it allowed German companies to keep their operations in Mexico open.[14]
Japanese response[edit]
The Japanese government, another nation mentioned in the Zimmerman Telegram, was already involved in World War I, on the side of the Allies against Germany. The government later released a statement that Japan was not interested in changing sides or attacking America.[40][41]
Autograph discovery[edit]
In October 2005, it was reported that an original typescript of the decoded Zimmermann Telegram had recently been discovered by an unnamed historian who was researching and preparing a history of the United Kingdom's Government Communications Headquarters (GCHQ). The document is believed to be the actual telegram shown to the American ambassador in London in 1917. Marked in Admiral Hall's handwriting at the top of the document are the words: "This is the one handed to Dr Page and exposed by the President." Since many of the secret documents in this incident had been destroyed, it had previously been assumed that the original typed "decrypt" was gone forever. However, after the discovery of this document, the GCHQ official historian said: "I believe that this is indeed the same document that Balfour handed to Page."[42]
As of 2006, there were six "closed" files on the Zimmermann Telegram which had not been declassified held by The National Archives at Kew (formerly the PRO).[43]