Historical story

The United States in the Great War

It is in the collective memory that the United States entered the war on the side of the Triple Entente in 1917 . Yet few people know why they participated in this conflict when they practice an isolationist policy. It was only April 6, 1917 , that the country declared war on Germany, thirty-two months were necessary for them to decide to participate, for the first time, in a European conflict.

Stay neutral at all costs!

Do you think Switzerland is the champion of neutrality? You are wrong, other countries have lent themselves to the game, in particular the United States. It is true that today in the collective consciousness the U.S. are known as "go to war", they are not afraid to enter into conflict. Yet in 1914, one thing is certain, the country did not want to go to war. Since the Monroe Doctrine of 1823, Europe no longer intervened in American affairs, otherwise it would be considered a threat to the peace of the country. In return, the United States no longer interfered in European issues. This doctrine preserves not only the North American continent but also Latin America from European colonizing aspirations.

In 1914, the entire population was reluctant to go to war. Indeed, Woodrow Wilson won re-election a year earlier to the White House on a simple promise:not to get involved in the European conflict. During his election, his slogan was “he kept us out of war”. (He saved us from the war.) In parallel, the United States will become over the years the first agricultural and industrial power in the world.

President Wilson announces his neutrality in Congress:

This neutrality in 1914 was essential to the country made up of immigrants from all the belligerent countries. Fueled by strong immigration, the state is divided on the attitude to maintain towards the war . Irish and Russian immigrant populations do not support UK and Russian policy. A majority of citizens saw no point in fighting against the Triple Alliance.

"All-out submarine warfare" a disastrous essay:the sinking of the Lusitania

From the beginning of the conflict, submarines have already been used for several decades! Invented in the 13th century by the British, each country has a few dozen. The Germans decide to use this weapon to break through the English blockade. The country first declared all-out war on February 4, 1915 in order to deprive the allies of their supplies from the colonies and neutral countries. This campaign was quickly stopped by the torpedoing of the liner Lusitania.

Less known than the sinking of the Titanic in 1912, the Lusitania remains today one of the most sinister. The Lusitania was one of the most luxurious boats of the time, it is at the forefront of modernity. The Americans discover on all the headlines of the sinking of the British ship which had left New Work six days earlier in the direction of Liverpool. A total of 2,165 passengers on board.

It only took 18 minutes for the ship to sink. Nearly 1,200 dead including 128 Americans such as art collector Hugh Lane, theater director Charles Frohman and Alfred Vanderbilt, one of the wealthiest men in the world. The American press is unleashed against Germany. It denounces German barbarism against neutral countries. The United Kingdom takes the opportunity to encourage these nations to position themselves against the Triple Alliance , and to volunteer to join the front lines at the front.

Walther Schwieger, commander of the submarine, sank the luxury liner without warning the ship and gave the order to torpedo it . The captain was accused of violating international law by attacking a defenseless passenger ship but also twice torpedoing it when it was already sinking ! However, according to his logbook, he would have fired only one torpedo, the ship was without a flag and carried a large quantity of ammunition. The English would have transported illegal cargo, (the ship was an armed auxiliary cruiser!) nearly 5,000 cases of shells, and other military cargo.

Schwieger is immediately repudiated by Wilhelm II, the Emperor of Germany. The commander is therefore nicknamed the baby killer because many children died in the sinking.

This shipwreck did not bring the United States into the war, but it made the country understand that Germany was not their ally . Moreover, it is still believed that the United Kingdom and France will win the war. The American troops are not trained and the ammunition that the country manufactures will no longer go to the English who are sorely lacking in it. Nevertheless, the disaster of the Lusitania suspended the policy excessively from September 18, 1915 .

The resumption of hostilities, a little closer to war

After three years of war that put countries and soldiers to the test, German maritime policy believed that winning the war meant cutting Britain's supply lines across the North Atlantic. Indeed, the country has suffered greatly from the maritime blockade in the Atlantic and Mediterranean. Thus, William II declared on January 31, 1917 the resumption of submarine warfare outrageously from February 1, 1917. Now the seas around the British Isles are considered a war zone and all ships are enemies. This policy also applies to neutral states, including the United States.

This choice is not without reason, during the sinking of the Lusitania, the American government had threatened Germany to go to war (a bluff like in Poker!) against a country with only 25 submarines. In February 1917, they owned 150. The Alliance hopes to loosen the grip of the Entente and hamper its supply. France and England, with an increasingly unstable Russian ally would be forced to capitulate before American help.
The allied and neutral losses are very important and push the Americans a little more towards the declaration of war .

Between diplomacy and secret services, James Bond always ready!

The German general staff is very worried. He knows that by unleashing all-out submarine warfare, the country will sink many American civilian ships. The latter will not remain without remains and therefore will finally come into conflict. Arthur Zimmermann, Minister of Foreign Affairs, proposes a rather original solution to delay the arrival of American troops. An alliance with Mexico and Japan. Why ? America would be caught in a gash, it will have to fight on two fronts and will prefer to defend its territory rather than landing in Europe.

On January 16, Zimmermann sends a coded telegram to the German Ambassador to the US, Bernstoff, telling him of his plan. It is intercepted and decrypted by the English secret services. They can't decrypt the entire message, but part of it is analyzed:

The English are convinced that if the United States is made aware of the plot fomented by Germany, the country will return to war quickly. Yet they cannot directly reveal the content of the telegram. First of all, the British secret service only cracked part of the code, an error is always possible. Otherwise, the Alliance will learn that their lines are tapped and will stop communicating on them. Finally, the English will have to announce that they are listening to exchanges from a neutral country which is rather embarrassing.

The solution is all found. The German ambassador to the United States and his counterpart in Mexico were to communicate the plan. A spy manages to steal a copy of the encrypted message in a simpler code than the previous one. There is no longer any doubt, the message is clear:it foresees the outbreak of all-out submarine warfare as well as the future wrath of the United States. However, with a view to an American entry into the war, the German ambassador proposed to the Mexican government to offer him the states of Texas, New Mexico and Arizona, the territories lost during the Mexican-American war. (1846-1848) and its financial support in exchange for a military alliance with their country. In addition, Zimmermann advises the country an alliance with Japan to facilitate the war.

Content of the Telegram:Extract from Le Figaro of March 02, 1917

British intelligence intercepted this message and waited for the right moment to send it to the White House. The scandal rocks American opinion. On April 6, 1917, the United States declared war on the Triple Alliance. The conflict therefore took a new turn, French and British welcomed the news with the greatest relief. A new ally enters the arena.

A superpower springs into action

"The Terrible Year marks the fundamental break. The very nature of the war changed by transforming it into an ideological conflict with the intervention of the United States and the Bolshevik revolution. The United States carries the banner of "just war" for the values ​​of democracy. Indeed, having no interest in Europe, they defend the principles "peace and freedom of the world (Wilson), fairly new notions for a country advocating isolationism. The country brings to the allies the strength of the first world industry, funding and men by the thousands while Germany is at the end of its tether.

Between April 1917 and May 1918, the Americans sent one million soldiers to Europe under General J.J. Pershing. The latter, according to Wilson's orders, insisted that their forces be separated from the other Allied armies until the last German offensives in March 1918 when this plan no longer held. 1918 is the time of the great offensives, Germany, liberated from the eastern front, sends its men to the west to forestall the arrival of American troops. The "Sammy" had the role of plugging the holes in the Allied lines, particularly during the Second Battle of the Marne. Two American attacks helped sustain the Allied offensive, that at Saint-Mihirl where they committed 500,000 soldiers and that at Meuse-Argonne which lasted from September to November and prompted the Germans to ask for an Armistice. /P>

The performance of American soldiers is neither worse nor better than that of allied or enemy forces. The living conditions are extremely difficult, trench warfare does not allow the use of tanks all the time. American casualties increased in the last months of the conflict , and at the same time, the worst flu epidemic in history hit both sides. 100,000 Americans lost their lives on the battlefields.

Our Guest Author:Clémentine

Hello everyone, my name is Clementine And like you, I am also a history buff! This has not always been the case, when I was younger I was allergic to it... I had the "hump" of history when I began to discover the Sun King, his loves, his wars and especially Versailles! Today, I try to transmit my passion on a daily basis, whether through my job as cultural manager of the Château de Thoiry or through research as a doctoral student with a study of the French nobility in the 19th century.


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Audoin Rouzeau S. (dir.) Becker J.J. (dir.), Encyclopedia in the Great War, Volume I and II, Perrin, 2012.
Harter H. The United States in the Great War, Tallandier, 2017.