The telegram was transmitted from Germany to Mexico via a transatlantic cable, which the Germans believed to be secure. You were wrong. When British agents intercepted the message and cryptographers in London decrypted it, the British government knew it finally had a way to get the United States to join the Allies and enter the war. All doubts about the authenticity of the telegram were dispelled by Zimmermann himself. At a press conference on March 3, 1917, he told an American journalist: “I cannot deny it. It`s true. Then, on March 29, 1917, Zimmermann gave a speech in the Reichstag in which he admitted that the telegram was authentic.  Zimmermann hoped that Americans would understand that the idea was that Germany would finance Mexico`s war with the United States only in the previous case of American entry into World War I. U.S. President Woodrow Wilson learned of the contents of the telegram on February 26; The next day, he proposed to Congress that the United States begin arming its ships against possible German attacks.
He also authorized the State Department to issue the Zimmermann telegram. On March 1, the news arrived. Germany had already sparked Wilson – and that of the American public – with its policy of unrestricted submarine warfare and its continuous attacks on American ships. Some of those in the United States, who were still waiting for neutrality, claimed that the telegram was a forgery. This idea was dispelled two days later when Zimmermann himself confirmed the authenticity. The Zimmermann telegram on DocsTeach asks students to analyze the telegram to determine whether the United States should have entered World War I based on the information and impact of the telegram. What led to the proposal for an alliance with Mexico? Zimmermann sent the telegram in anticipation of the resumption of unrestricted submarine warfare, an act that the German government believed would likely lead to war with the United States. Zimmermann hoped that tensions with Mexico would slow the delivery of supplies, ammunition and troops to the allies if the United States was tied to its southern border. However, many Americans, especially German and Irish Americans, wanted to avoid conflicts in Europe.
Since the public had been falsely informed that the telegram had been stolen in decrypted form in Mexico, the message was initially generally considered a sophisticated forgery by British intelligence. This belief, which was not limited to pacifist and pro-German lobbies, was promoted by German and Mexican diplomats alongside some American newspapers, notably the Hearst press empire. This posed a dilemma for the Wilson administration. With the evidence provided confidentially to the US by the British, Wilson realized that the message was genuine – but he could not disclose the evidence without compromising the British decryption operation. British decryptors received two copies of Zimmermann`s coded telegram, and they were able to break the cipher with a broken code and compare the telegrams. Zimmermann was not only willing to finance an adventure by the Mexican government to recover the territory lost to the United States, but wanted Mexico to intervene with Japan to get Japan to change sides in the war. (Japan played a limited role against Germany during World War I.) The revelation of the contents angered Americans, especially after German Foreign Minister Arthur Zimmermann publicly admitted on March 3 that the telegram was genuine, helping to win support for the U.S. declaration of war on Germany in April.  Decryption has been described as Britain`s most important intelligence triumph of the First World War, and one of the earliest occasions when signals intelligence influenced world affairs.  The Zimmermann Telegram is a coded note from German Foreign Minister Arthur Zimmermann from January 1917 with a message to the Mexican government.
The memo called on the Mexican government to declare war on the United States and promised to help Mexico retake Texas, Arizona and New Mexico. The British intercepted the telegram, decrypted it and showed it to U.S. President Woodrow Wilson in February. It was published in U.S. newspapers on March 1. As the Lusitania always irritated the Americans, the public reaction in the United States against Germany was so strong that it became inevitable that the United States would join the war on the side Germany was fighting. The reception of the text of the Zimmermann telegram from London on the 24th. In February 1917, Wilson did not opt for armed neutrality, but he lost all confidence in the German government. Moreover, the publication of the telegram in the press on 1 March triggered the first national call for war with Germany. After the news broke in the telegram, the Japanese ambassador to Germany called it “too ridiculous for words,” and the Mexican government officially declined the offer on April 14, 1917. Zimmermann resigned as foreign minister in August 1917. But the influence of the Telegram on American public opinion on Germany`s intentions was an important factor in the United States` decision to enter World War I.
Zimmermann Telegram, also known as Zimmermann`s Note, an encrypted telegram sent by German Foreign Minister Arthur Zimmermann to the German Minister in Mexico on January 16, 1917. The memo revealed a plan to renew unrestricted submarine warfare and form an alliance with Mexico and Japan if the United States declared war on Germany. The message was intercepted by the British and transmitted to the United States; its publication caused outrage and contributed to the entry of the United States into World War I. For the first story, the British received the coded text of the telegram from the Mexican Commercial Telegraph Bureau. The British knew that since the German embassy in Washington would transmit the message by commercial telegraph, the Mexican telegraph office would have the encrypted text. “Mr. H,” a British agent in Mexico, bribed an employee of the commercial telegraph company to obtain a copy of the message. (Sir Thomas Hohler, the British ambassador to Mexico, claimed that “Mr. H” or at least involved in the interception in his autobiography. [ref. needed]) This coded text could be shown to Americans without embarrassment. The First World War was a conflict that affected many countries from 1914 to 1918.
The countries involved in the war were part of the Entente or allied powers (Great Britain, France, Russia, Serbia and their allies) and the Central Powers (composed of three empires, the German, Austro-Hungarian and Ottoman empires, as well as the Kingdom of Bulgaria and their allies). More than 15 million people have sacrificed their lives in one of the deadliest wars in history. More than 70 million people took part in the war, including 60 million Europeans. Zimmermann`s office sent the telegram to the German Embassy in the United States for transmission to Eckardt in Mexico. It has traditionally been claimed that the telegram was sent by three channels: by radio and also by two transatlantic telegraph cables operated by neutral governments (the United States and Sweden) for the use of their diplomatic services, but it has been found that two methods have been used. The Germans handed over the embassy to the U.S. embassy in Berlin, and then it was transmitted by diplomatic telegram first to Copenhagen and then to London for transatlantic cable transmission to Washington.  The events of early 1917 would change this hope. Frustrated by the effective British naval blockade, Germany broke its promise to limit submarine warfare on February 1, 1917.
In response to the violation of the Sussex promise, the United States severed diplomatic relations with Germany. A few weeks later, on the 24th. The British delivered the Zimmermann telegram to the United States. Government in an effort to capitalize on growing anti-German sentiment in the United States. The American press published news about the telegram on March 1. On April 6, 1917, the United States Congress officially declared war on Germany and its allies. At first, many in the United States thought that the Zimmermann telegram was a forgery of the British. Arthur Zimmermann himself put an end to this speculation when he admitted on 29 March that the telegram was genuine.