Zimmermann telegram
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.
[4] The message came in the form of a coded telegram dispatched by Arthur Zimmermann, the Staatssekretär (a top-level civil servant, second only to their respective minister) in the Foreign Office of the German Empire on January 17, 1917.
[5] 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.
wollen Vorstehendes Präsidenten streng geheim eröffnen, sobald Kriegsausbruch mit Vereinigten Staaten feststeht und Anregung hinzufügen, Japan von sich aus zu fortigem Beitritt einzuladen und gleichzeitig zwischen uns und Japan zu vermitteln.Bitte Präsidenten darauf hinweisen, daß rücksichtslose Anwendung unserer U-boote jetzt Aussicht bietet, England in wenigen Monaten zum Frieden zu zwingen.
Please call to the attention of the President of Mexico that the employment of ruthless submarine warfare now promises to compel England to make peace in a few month [sic].
[9] 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 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.
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.
[18] 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.
[14] 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.
It went by radio, and passed via telegraph cable inside messages sent by diplomats of two neutral countries (the United States and Sweden).
[24] However, that put German diplomats in a precarious situation since they relied on the United States to transmit Zimmermann's note to its final destination, but the message's unencrypted contents would be deeply alarming to the Americans.
[25] 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.
[27] 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.
(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.)
The German Foreign Office refused to consider that their codes could have been broken but sent Von Eckardt on a witch hunt for a traitor in the embassy in Mexico.
On February 23, Page met with British Foreign Minister Arthur Balfour and was given the codetext, the message in German, and the English translation.
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.
[32] General John J. Pershing had long been chasing the revolutionary Pancho Villa for raiding into American territory and carried out several cross-border expeditions.
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.
[36] Wilson considered another military invasion of Veracruz and Tampico in 1917–1918,[37][38] to pacify the Isthmus of Tehuantepec and Tampico oil fields and to ensure their continued production during the civil war,[38][39] but this time, Mexican President Venustiano Carranza, recently installed, threatened to destroy the oil fields if the US Marines landed there.
[42][43] 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.
