Zimmermann Telegram

The First World War helped the USA economy with exported goods to Allied countries increasing from $825 million in 1914 to $3.2 billion in 1916. This made it possible for Britain and France to keep fighting the war against the Central Powers and this influenced Germany's decision to announce its unrestricted submarine warfare policy. Opinion against Germany hardened after the sinking of the Lusitania. Some newspapers in the United States called on President Woodrow Wilson to declare war on Germany. However, he refused to do this as he wanted "to preserve the world's respect by abstaining from any course of action likely to awaken the hostility of either side in the war, and so to keep the United States free to undertake the part of peacemaker". (1)

President Wilson warned the Germans about the consequences of causing the deaths of American citizens. William Jennings Bryan, Wilson's Secretary of State disagreed with this approach. He also pointed out that by traveling on British vessels, which were at risk of attack, "an American citizen can, by putting his own business above his regard for this country, assume for his own advantage unnecessary risks and thus involve his country in international complications" and suggested a more even-handed policy. Bryan eventually resigned in June 1915, by raising the question "why be so shocked by the drowning of a few people, if there is to be no objection to starving a nation." (2)

Wilson replaced Bryan with the pro-Allied Robert Lansing. Wilson also announced an increase in the size of the US armed forces. In the 1916 Presidential election campaign, Woodrow Wilson stressed his policy of neutrality and his team used the slogan: "He kept us out of the war". However, he did make a speech after his victory he warned Germany that submarine warfare resulting in American deaths would not be tolerated, saying: "The nation that violates these essential rights must expect to be checked and called to account by direct challenge and resistance. It at once makes the quarrel in part our own." (3)

Zimmermann Telegram

On 16th January 1917, the German Foreign Secretary, Arthur Zimmermann, sent a coded telegram to the ambassador in Mexico City where he informed him that Germany intended to begin unrestricted submarine warfare on 1st February. He also instructed the ambassador to propose an alliance with Mexico if war broke out between Germany and the United States. In return, the telegram proposed that Germany and Japan would help Mexico regain the territories that it lost to the United States in 1848 (Texas, New Mexico and Arizona). (4)

Clifford K. Berryman, Zimmermann Telegram (February, 1917)
Clifford K. Berryman, Zimmermann Telegram (February, 1917)

On the outbreak of the First World War the Admiralty established the Government Code and Cypher School (GCCS). People such as Alastair Denniston, Alfred Dilwyn Knox and Frank Birch were involved in intercepting, decrypting, and interpreting naval staff German and other enemy wireless and cable communications. GCCS obtained a copy of the Zimmermann Telegram and after it was decrypted it was passed to the American government. (5)

United States enters the First World War

When he received details of the telegram, President Woodrow Wilson did not immediately declare war and instead commented, "We are the sincere friends of the German people and earnestly desire to remain at peace with them. We shall not believe they are hostile to us unless or until we are obliged to believe it". (6)

On 21st March the United States tanker, The Healdton, was sunk by a German submarine while in a specially declared "safety zone" in Dutch waters. Twenty American crewmen were killed. Wilson called a meeting with his Cabinet and it unanimously decided to go to war. On 2nd April, President Wilson asked for permission to go to war. This was approved in the Senate on 4th April by 82 votes to 6, and two days later, in the House of Representatives, by 373 to 50. Still avoiding alliances, war was declared against the German government (rather than its subjects). (7)

Germany was confident that they could bring Britain to collapse before American action became effective. As A. J. P. Taylor pointed out: "They nearly succeeded. The number of ships sunk by U-boats rose catastrophically. In April 1917 one ship out of four leaving British ports never returned. That month nearly a million tons of shipping were sunk, two thirds of it British. New building could replace only one ton in ten. Neutral ships refused cargoes for British ports. The British reserve of wheat dwindled to six weeks' supply." (8)

Frank Holland, John Bull Magazine (1917)
Frank Holland, John Bull Magazine (1917)

When the USA declared war in April 1917, Wilson sent the American Expeditionary Force (AEF) under the command of General John Pershing to the Western Front. The Selective Service Act, drafted by Brigadier General Hugh Johnson, was quickly passed by Congress. The law authorized President Wilson to raise a volunteer infantry force of not more than four divisions. Pershing arrived in France in June 1917, with his troops and initially stated that they were at the disposal of General Ferdinand Foch. "It was an inspiring gesture - although in practice he continued to keep a tight hold on his troops and, with rare exceptions, only allowed them to take over parts of the front as complete divisions." (9)

Primary Sources

(1) Arthur Zimmermann, telegram to Heinrich von Eckardt, the German ambassador to Mexico (19th January, 1917)

We intend to begin on the first of February unrestricted submarine warfare. We shall endeavor in spite of this to keep the United States of America neutral. 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 the lost territory in Texas, New Mexico, and Arizona. The settlement in detail is left to you. You will inform the President 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. 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.

Student Activities

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Walter Tull: Britain's First Black Officer (Answer Commentary)

Football and the First World War (Answer Commentary)

Football on the Western Front (Answer Commentary)

Käthe Kollwitz: German Artist in the First World War (Answer Commentary)

American Artists and the First World War (Answer Commentary)

Sinking of the Lusitania (Answer Commentary)


(1) The Manchester Guardian (10th May, 1915)

(2) Donald E. Schmidt, The Folly of War: American Foreign Policy 1898–2005 (2005) page 79

(3) Woodrow Wilson, speech (2nd September, 1916)

(4) Arthur Zimmermann, telegram to the German ambassador in Mexico City (16th January 1917)

(5) Michael Smith, Station X: The Codebreakers of Bletchley Park (1998) page 11

(6) August Heckscher, Woodrow Wilson (1991) page 428

(7) Martin Gilbert, First World War (1994) page 317

(8) A. J. P. Taylor, English History: 1914-1945 (1965) page 122

(9) Basil Liddell Hart, History of the First World War (1930) page 371