The Zimmermann Telegram and American Entry into World War I

Zimmermann Telegram, January 19, 1917. (National Archives)The fact that the telegram before him bore Arthur Zimmermann’s name made its contents that much harder for Walter Hines Page to believe. Page was the American ambassador to Great Britain and on a cold London morning in late February 1917 the British foreign minister Arthur Balfour stood before him with what Page called a "bombshell." Page had had high hopes for Zimmermann, recently named the new German foreign minister. Zimmermann was a member of the middle class, not the aristocracy that President Wilson’s administration so deeply mistrusted. He had thus far said all the right things and shown a receptiveness to Wilson’s cherished efforts to end the war through peace negotiations. The telegram Page stared at in numb disbelief proved beyond the shadow of a doubt that Zimmermann had been lying all along. Far from being a man the Americans could see as a partner for peace, he was instead the author of the most notorious message Page had ever seen.[1]

Balfour, knowing full well that the telegram might lead the Americans to enter the war on Britain and France’s side, had nevertheless hesitated to show it to Page. The Royal Navy admiral whose office, codenamed Room 40, had intercepted and decoded the telegram had also been wracked with doubt about what to do. Although Admiral Sir William Hall knew exactly how important the telegram was, he had to find a way to show it to the Americans without revealing that his office had broken the German codes. Once the Germans learned that their codes and ciphers were no longer secure, they would stop using them and a veritable gold mine of information would stop flowing into Hall’s office. Only once he was convinced that he had found a way to protect his precious secret did he give the telegram to Balfour.

Page picked up the telegram one more time and read the words that he knew would force the United States into the war it had been trying desperately to avoid for three years:

We intend to begin on the first of February unrestricted submarine warfare STOP We shall endeavor in spite of this to keep the United States of America neutral STOP In the event of this not succeeding, we make Mexico a proposal of alliance on the following basis make war together, make peace together, generous financial support and an understanding on our part that Mexico is to reconquer lost territory in Texas, New Mexico, and Arizona STOP The settlement in detail is left to you STOP You will inform the President [of Mexico] of the above most secretly as soon as the outbreak of war with the United States of America is certain and add the suggestion that he should, on his own initiative, invite Japan to immediate adherence and at the same time mediate between Japan and ourselves STOP Please call the President’s attention to the fact that the ruthless employment of our submarines now offers the prospect of compelling England in a few months to make peace STOP Signed ZIMMERMANN[2]

It did not surprise Page that the Germans intended to resume sinking merchant ships. He knew the Germans were contemplating such a move and that the United States Congress was even then debating a bill to arm merchant ships in response. The shocking parts of the telegram involved Mexico and Japan. Germany was effectively proposing an alliance to tear the United States apart in the event of American belligerence. The telegram was therefore an act of war. It was also so obviously in Britain’s interests to share it with him that Page knew his countrymen would suspect it was a forgery or a British trick.

Page knew, as did Wilson, that German agents were active in Mexico. They were trying to take advantage of the extremely poor state of Mexican-American relations that had existed since the start of the Mexican Revolution in 1911. Wilson had sent American forces to intervene in Mexico in an attempt to remove leaders he disliked. In his own words, he was trying to teach the Mexicans to elect good men. Most significantly, he had ordered American sailors and marines into Veracruz for six months in 1914, partly to prevent the German government from sending arms to the Mexican strongman Victoriano Huerta. Violence in Veracruz eventually resulted in the deaths of nineteen Americans and 129 Mexicans. As part of the fallout, the Americans stopped sending arms to another aspirant to power, Mexican General Pancho Villa. Villa’s men responded by raiding New Mexico in March 1916, killing eighteen Americans. America’s ambassador in Berlin was convinced that the Germans were supporting Villa, hoping that if he became president he would grant Germany the right to build a port on Mexico’s Caribbean coastline.[3] An American expedition to find and punish Villa commanded by General John Pershing failed, leaving American relations with Mexico on a hair trigger.

American relations with Japan were also tense. Several western states had passed or were considering laws that banned Japanese men and women (including American citizens) from owning land. Word had also reached Washington of Japanese arms sales to Mexico as well as negotiations to build a Japanese naval base on Mexico’s Pacific coast. One of the sites mentioned was on the Baja peninsula where a Japanese cruiser suddenly appeared in April 1915. The Americans saw these events as a violation of the Monroe Doctrine and a source of significant concern. The Wilson administration also knew that the Germans were trying to sway the Japanese with promises of territorial gains in China if they would declare war on Russia.

The Germans themselves were a headache for Wilson, who was trying as hard as he could to keep the United States neutral. The Germans were not making it easy for him. The sinking of the Lusitania in May 1915, which killed 128 Americans, had turned most Americans anti-German, if not yet pro-Allied. German spies were also active across the United States. They pulled off a spectacular incident of what we would today call state-sponsored terrorism when they blew up the Black Tom munitions depot in Jersey City, New Jersey, in April 1916. The blast killed seven people and was powerful enough to shatter windows as far away as Times Square. Suspicion initially fell on a workman who had lit fire pots to keep mosquitos away. By the time investigators uncovered a German connection, the perpetrators had vanished.

Still, Wilson did not want to take the nation to war in large part because he believed that only as a neutral statesman could he bring the two sides to peace. He also knew that neutrality was popular with key constituencies of his Democratic Party, including the rural South and Midwest and the large Irish and German American communities whose sympathies were decidedly anti-English.

But even while Wilson was feeling pressure from the isolationists to stay out of the war, his biggest political rival, former President Theodore Roosevelt, was leading a vocal group that was urging Wilson to stand up to Germany. Already colored by their pro-British and pro-French sensibilities and furious at German atrocities in Belgium and on the high seas, Roosevelt and his allies urged America to get ready to fight a war to defend democracy and freedom in Europe. Roosevelt began giving speeches and writing regular newspaper articles lambasting Wilson as a coward who refused to stand up for American values and American rights. The longer the war went on and the more Germany infringed on American interests, the harsher Roosevelt’s tone grew. He and his political allies had begun voluntary camps at Plattsburg, New York, to train young men in military service, although the real purpose of the movement was to shame Wilson into ordering the American Army to prepare for war.

Wilson’s extremely narrow victory in the 1916 election had given him four more years, but it had not solved his foreign policy dilemmas. Mexico remained an ulcer and Pershing’s inability to find Villa was a humiliation. Nor had the election silenced Roosevelt, who had supported Wilson’s opponent, Charles Evans Hughes. Roosevelt and his friend, Massachusetts Senator Henry Cabot Lodge, eyed a Republican victory in the 1918 midterm election, and Roosevelt had begun to hint that he might run for the presidency in 1920. Facing all of these problems and distant even from his own Cabinet, it was perhaps not surprising that Wilson seemed confused and unsure of how to deal with a world crisis that threatened to pull America into a war in Mexico or, worse still, into the trenches of the western front.

The telegram that Page transmitted to Washington was indeed a bombshell for Wilson. Although Wilson trusted Page’s assurances that the telegram was genuine, Wilson knew that he would need more than the ambassador’s word to convince the American people and the isolationists in Congress. He therefore sent an American intelligence expert to Room 40 to verify both the telegram and the cipher used to decode it. Admiral Hall had been reluctant, but eventually agreed, especially once he figured out how to protect his source. Hall’s men had intercepted a second version of the telegram, sent from the German embassy in Washington to the German mission in Mexico. The second telegram contained just enough changes in wording from the original that when the Americans published it, the Germans would likely conclude that someone in Mexico had leaked it. The existence of Room 40 could therefore remain Britain’s most important wartime secret.

The Zimmermann telegram appeared in American newspapers on March 1 and set off the reactions Wilson and Page had expected. For many Americans, the potential combination of Mexico, Japan, and Germany represented nothing less than a nightmare. Newspapers across the country equated the telegram with a German declaration of war. Many of them also used racist imagery about the Japanese and Mexicans to depict them as servile agents of the smarter and more highly developed Germans. The fear was greatest in the West and Southwest, regions that had traditionally been isolationist. The Zimmermann telegram painted a future for people from Texas to California of invasion, the loss of their land, and conquest by the soldiers of Mexico and Japan. Supposition that the Germans might seize Canada from Britain in the event they won the war further stoked American fears. In a flash the war was no longer about events in Europe. It was now about threats to America itself.

Also predictably, many of Wilson’s political opponents refused to believe the telegram’s legitimacy. Republicans, Irish Americans, German Americans, and even some members of Wilson’s own party either thought the British were playing an elaborate ruse on the naïve president or refused to believe any diplomat could send anything as stupid as that telegram. Wilson shared all the information he had with key isolationist senators who were even then preparing to filibuster the bill to arm merchant ships. Zimmermann gave Wilson one more gift by admitting to an amazed German media that he had indeed sent the telegram. Zimmermann saw no value in denying what the British and Americans could presumably prove. He also saw the value of having his offer of alliance out in the open, allowing him to pursue further diplomatic negotiations with the Japanese and Mexican governments. Japan’s ambassador to Germany, however, called the idea of an alliance "too ridiculous for words," and, after giving it some thought, the Mexicans, too, backed away.[4] Zimmermann’s gamble had failed.

It remained to be seen, however, how Wilson would react. Roosevelt was so incensed he told a friend that if the President did not declare war he would "skin him alive." He then petitioned Wilson for the right to raise and command his own division and lead it in combat in France. Wilson, predictably, refused, leading Roosevelt to remark "I don’t understand. After all, I’m only asking to be allowed to die."[5] An irate House of Representatives, which had been hotly debating the issue of arming merchant ships, reversed course and voted 500 to 13 in favor. It also added a provision to the bill authorizing the President to use the armed forces of the United States in any way he saw fit to protect American property and lives. Although it was unclear if the Senate would follow suit, it was perfectly clear that the mood in the country had changed dramatically. The isolationist and pro-German press, unable to defend Zimmermann or deny the telegram’s existence, simply went quiet or voiced support for the United States.

On March 20, with the American media still enraged, Wilson met with his Cabinet and found them for the first time unanimously in favor of war. Even the intensely pacifist Secretary of the Navy, Josephus Daniels, voiced his support for war. The next day Wilson told Congress to assemble on April 2, a full two weeks earlier than scheduled, to hear him address "grave matters of national policy." Zimmermann’s telegram had been the final straw. Wilson asked Congress for a declaration of war and took the first steps toward leading his nation into the most terrible war the world had ever known.

[1] Burton J. Hendrick, The Life and Letters of Walter Hines Page (Garden City, NY: Doubleday, 1925), 3:324.

[2] Details of the process of decoding the telegram, as well as much else, can be found in Barbara W. Tuchman, The Zimmermann Telegram (New York: Ballantine Books, 1958).

[3] Tuchman, The Zimmermann Telegram, 95.

[4] Hendrick, The Life and Letters of Walter Hines Page, 3:352.

[5] Edward J. Renehan Jr. The Lion’s Pride: Theodore Roosevelt and His Family in Peace and War (New York: Oxford University Press, 1998), 129. All five of Roosevelt’s children served in World War I. His son Quentin died when the Germans shot down his plane during the Second Battle of the Marne.

Michael S. Neiberg is the author or editor of more than a dozen books, most of them dealing with World War I, its causes, and its global impacts. His most recent book is Dance of the Furies: Europe and the Outbreak of World War I (2011). Currently at work on a history of the liberation of Paris in 1944, he is a former Harry Frank Guggenheim fellow and is a professor of history at the United States Army War College.

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