Zimmermann telegram

The message came in the form of a coded telegram dispatched by Arthur Zimmermann, the (a top-level civil servant, second only to their respective minister) in the Foreign Office 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 presumed would almost certainly lead to war with the United States. The telegram instructed Von Eckardt that if the United States appeared certain to enter the war, he was to approach the Mexican government with a proposal for military alliance with funding from Germany. The decoded telegram was as follows: Original (German): Translated: ==History==

Previous German efforts to promote war 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. The Germans had aided in arming Mexico, as shown by the 1914 Ypiranga incident. 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. 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, 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. 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. 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. The Zimmermann telegram was part of an effort carried out by the Germans to postpone the transportation of supplies and other war materials from the United States to the Allies, which were at war against Germany. The main purpose of the telegram was to make the Mexican government declare war on the United States in hopes of tying down American forces and slowing the export of American arms. The German High Command believed that it could defeat the British and French on the Western Front and strangle Britain with unrestricted submarine warfare before American forces could be trained and shipped to Europe in sufficient numbers to aid the Allies. The Germans were encouraged by their successes on the Eastern Front to believe that they could divert large numbers of troops to the Western Front in support of their goals. ==Mexican response==

Mexican President Venustiano Carranza assigned a military commission to assess the feasibility of the Mexican takeover of their former territories contemplated by Germany. The generals concluded that such a war was unwinnable for the following reasons: • Mexico was in the midst of a civil war, and Carranza's position was far from secure; Carranza himself was later assassinated, in 1920. Picking a fight with the United States would have prompted the U.S. to support one of his rivals. • The United States was far stronger militarily than Mexico. Even if Mexico's military forces had been completely united and loyal to a single government, no serious scenario existed under which it could have invaded and won a war against the United States. Indeed, much of Mexico's military hardware of 1917 reflected only modest upgrades since the Mexican–American War 70 years before, which the U.S. had won. • The German government's promises of "generous financial support" were very unreliable. It had already informed Carranza in June 1916 that it could not provide the necessary gold needed to stock a completely independent Mexican national bank. Even if Mexico received financial support, it would still need to purchase arms, ammunition, and other needed war supplies from the ABC nations (Argentina, Brazil, and Chile), which would strain relations with them, as explained below. • Even if by some chance Mexico had the military means to win a conflict against the United States and to reclaim the territories in question, it would have had severe difficulty conquering and pacifying a large English-speaking population which had long enjoyed self-government and was better supplied with arms than were most other civilian populations. After the military invasion of Veracruz in 1914, Mexico did not participate in any military excursion with the United States in World War I. 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. ==British interception==

codebreakers. Since the word Arizona was not in the German codebook, it had to be split into phonetic syllables. 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 allowed the British to decrypt the Zimmermann telegram. Zimmermann's office sent the telegram to the German embassy in the United States for retransmission to Von Eckardt in Mexico. It has traditionally been understood that the telegram was sent over three routes. It went by radio, and passed via telegraph cable inside messages sent by diplomats of two neutral countries (the United States and Sweden). Direct telegraph transmission of the telegram was impossible because the British had cut the German international cables at the outbreak of war. However, Germany could communicate wirelessly through the Telefunken plant, operating under Atlantic Communication Company in West Sayville, New York, where the telegram was relayed to the Mexican Consulate. Ironically, the station was under the control of the US Navy, which operated it for Atlantic Communication Company, the American subsidiary of the German entity. The Swedish diplomatic message holding the Zimmerman telegram went from Stockholm to Buenos Aires over British submarine telegraph cables, and then moved from Buenos Aires to Mexico over the cable network of a United States company. After the Germans' telegraph cables had been cut, the German Foreign Office appealed to the United States for use of their diplomatic telegraphic messages for peace messages. President Wilson agreed in the belief both that such co-operation would sustain continued good relations with Germany and that more efficient German–American diplomacy could assist Wilson's goal of a negotiated end to the war. The Germans handed in messages to the American embassy in Berlin, which were relayed to the embassy in Denmark and then to the United States by American telegraph operators. The Germans assumed that this route was secure and so used it extensively. Thus the Germans were able to persuade US Ambassador James W. Gerard to accept Zimmermann's note in coded form, and it was transmitted on January 16, 1917. In Room 40, Nigel de Grey had partially decoded the telegram by the next day. By 1917, the diplomatic code 13040 had been in use for many years. Since there had been ample time for Room 40 to reconstruct the code cryptanalytically, it was readable to a fair degree. Room 40 had obtained German cryptographic documents, including the diplomatic code 3512 (captured during the Mesopotamian campaign), which was a later updated code that was similar to but not really related to code 13040, and naval code SKM (Signalbuch der Kaiserlichen Marine), ⁠which was useless for decoding the Zimmermann telegram but valuable to decode naval traffic, which had been retrieved from the wrecked cruiser SMS Magdeburg by the Russians, who passed it to the British. Disclosure of the telegram would sway American public opinion against Germany if the British could convince the Americans that the text was genuine, but the Room 40 chief William Reginald Hall was reluctant to let it out because the disclosure would expose the German codes broken in Room 40 and British eavesdropping on United States diplomatic traffic. Hall waited three weeks during which de Grey and cryptographer William Montgomery completed the decryption. On February 1, Germany announced resumption of "unrestricted" submarine warfare, an act that led the United States to break off diplomatic relations with Germany on February 3. For the first story, the British obtained the coded text of the telegram from the Mexican commercial telegraph office. The British knew that since the German embassy in Washington would relay the message by commercial telegraph, the Mexican telegraph office would have the coded text. "Mr. H", a British agent in Mexico, bribed an employee of the commercial telegraph company for a copy of the message. Sir Thomas Hohler, the British ambassador in Mexico, later claimed to have been "Mr. H" or at least to have been involved with the interception in his autobiography. The coded text could then be shown to the Americans without embarrassment. Moreover, the retransmission was encoded with the older code 13040 and so by mid-February, the British had the complete text and the ability to release the telegram without revealing the extent to which the latest German codes had been broken. (At worst, the Germans might have realized that the 13040 code had been compromised, but that was a risk worth taking against the possibility of United States entry into the war.) Finally, since copies of the 13040 code text would also have been deposited in the records of the American commercial telegraph company, the British had the ability to prove the authenticity of the message to the American government. Page then reported the story to Wilson on February 24, 1917, including details to be verified from telegraph-company files in the United States. Wilson felt "much indignation" toward the Germans and wanted to publish the Zimmermann Telegraph immediately after he had received it from the British, but he delayed until March 1, 1917. ==U.S. response==

Many Americans then held anti-Mexican as well as anti-German views. Mexicans had a considerable amount of anti-American sentiment in return, some of which was caused by the American occupation of Veracruz. General John J. Pershing had long been chasing the revolutionary Pancho Villa for raiding into American territory and carried out several cross-border expeditions. News of the telegram further inflamed tensions between the United States and Mexico. However, many Americans, particularly those with German or Irish ancestry, wished to avoid the conflict in Europe. Since the public had been told falsely that the telegram had been stolen in a decoded form in Mexico, the message was at first widely believed to be an elaborate forgery created by British intelligence. That belief, which was not restricted to pacifist and pro-German lobbies, was promoted by German and Mexican diplomats alongside some antiwar American newspapers, especially those of the Hearst press empire. On February 1, 1917, Germany had begun unrestricted submarine warfare against all ships in the Atlantic bearing the American flag, both passenger and merchant ships. Two ships were sunk in February, and most American shipping companies held their ships in port. Besides the highly-provocative war proposal to Mexico, the telegram also mentioned "ruthless employment of our submarines". Public opinion demanded action. Wilson had refused to assign US Navy crews and guns to the merchant ships, but once the Zimmermann note was public, Wilson called for arming the merchant ships although antiwar members of the US Senate blocked his proposal. The Wilson administration nevertheless remained with a dilemma. The British had provided evidence confidentially to the United States that the message was genuine, but Wilson could not make the evidence public without compromising the British codebreaking operation. This problem was resolved, however, when doubts as to the authenticity of the telegram were removed by Zimmermann himself. At a press conference on March 3, 1917, he told an American journalist, "I cannot deny it. It is true." Then, on March 29, 1917, Zimmermann gave a speech in the Reichstag in which he admitted that the telegram was genuine. Zimmermann hoped that Americans would understand that the idea was that Germany would not fund Mexico's war with the United States unless the Americans joined World War I. Nevertheless, in his speech Zimmermann questioned how the Washington government obtained the telegram. According to Reuters news service, Zimmermann told the Reichstag, "the instructions...came into its hands in a way which was not unobjectionable." Wilson considered another military invasion of Veracruz and Tampico in 1917–1918, to pacify the Isthmus of Tehuantepec and Tampico oil fields and to ensure their continued production during the civil war, but this time, Mexican President Venustiano Carranza, recently installed, threatened to destroy the oil fields if the US Marines landed there. ==Japanese response==

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. ==Autograph discovery==

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. 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." As of 2024, there were six "open" files on the Zimmermann telegram which have not been declassified held by The National Archives at Kew (formerly the PRO). ==See also==