Zimmerman telegram
The Zimmermann Telegram was a telegram dispatched to the government of Mexico by the Foreign Secretary of the German Empire, Arthur Zimmermann, on January 16, 1917, at the height of World War I.
The telegram was intercepted and decrypted by codebreakers Nigel de Grey and William Montgomery of the British Naval Intelligence unit, Room 40, under Admiral William R. Hall. This was made possible because the code the Foreign Office used (0075) had been partially cryptanalyzed using, amongst other techniques, captured plaintext messages. Zimmermann's message proposed that Mexico should ally itself with Germany if the United States were to enter the war. It also suggested that were Mexico to launch a pre-emptive strike on the United States, it would have Germany's backing and would be rewarded with Texas, New Mexico and Arizona if the Central Powers and their allies won the war. It urged Mexico to mediate between Germany and Japan to convince the Japanese to enter the war against the US.
The British government, which wanted to expose the incriminating telegram, faced a dilemma: if it baldly produced the actual telegram, the Germans would suspect that their code was broken; and if it did not, it would lose a promising opportunity to draw the United States into World War I – the message was sent during a period when anti-German feeling in the United States was running particularly high, following the loss of some two hundred US lives to German submarine attacks.
The British government knew that a decrypted version of the telegram existed in Mexico and that if they could lay their hands on it, they could pretend that the telegram was obtained as a result of espionage activity in Mexico and not as a result of code breaking. Therefore, they contacted a British agent in Mexico, known only as Mr. H., who managed to get a copy of the Mexican version of the telegram.
The telegram was delivered by Admiral Hall to the British Foreign Minister, Arthur James Balfour, who in turn contacted the US ambassador in Britain, Walter Page, and delivered the telegram to him on February 23. Two days later he relayed it to President Woodrow Wilson.
The general sentiment in the USA was generally as anti-Mexican as it was anti-German. General John J. Pershing had long been chasing bandit-cum-revolutionary Pancho Villa, who had carried out several cross-border raids. This was a great expense to the US government, and Wilson was leaning towards discontinuing the search until new elections were held in Mexico, a new government installed, and a new constitution promulgated (a constitutional convention, which would adopt the 1917 Constitution of Mexico, was underway at the time). News of the telegram exacerbated tensions between the USA and Mexico, since such a treaty, if in place, would have hindered the election of a new Mexican government more friendly to US interests.
On March 1, the US Government gave the plaintext of the telegram to the Press. Initially the American public believed the telegram to be a fraud designed to bring them into the war on the Allied side. This opinion was bolstered by German, Mexican and Japanese diplomats, and by the American pacifist and pro-German lobbies, who all denounced the telegram as a forgery. However, in a startlingly unexpected move, Zimmermann confirmed its authenticity in public, two days after its publication.
Although the telegram began by stating that Germany was most interested in maintaining American neutrality while attacking its shipping, this confirmation of its basic enmity evoked an outpouring of anti-German sentiment. Wilson responded to this manifestation of German hostility towards the US by asking Congress to arm American ships so that they could fend off potential German submarine attacks. One month later, on April 2, Wilson asked Congress to declare war on Germany. Four days later, on April 6, 1917, Congress complied, bringing the United States into World War I.
German submarines had previously attacked US ships near England, so the telegram was not the only cause of the war; it did, however, play a critical role in swaying US public opinion. It was perceived as especially perfidious that the telegram was first transferred from the US embassy in Berlin to the German embassy in Washington before being passed on to Mexico. Once the American public believed the telegram to be real, it became all but inevitable that the USA would join the Great War.
References
- Room 40: British Naval Intelligence, 1914-1918, by Patrick Beesly. New York: Harcourt, Brace, Jovanovich, 1982 ISBN 0-15-178634-8
