Log in Sign up
Back to Discover
🏛️

Zimmermann telegram

history Maturity 11-13 war conflict
This article covers sensitive topics: war_conflict. Parents can manage visibility in Parental Controls.

A secret note was sent long ago.

Zimmermann Telegram as Received by the German Ambassador to Mexico - NARA - 302025.jpg
Zimmermann Telegram as Received by the German Ambassador to Mexico - NARA - 302025.jpg
It was a hidden message. It tried to start a fight. This note made people very mad. It changed how many countries acted.
Arthur Zimmermann.png
Arthur Zimmermann.png
Can you imagine a secret note?

52 words

A secret note was sent long ago.

Zimmermann Telegram as Received by the German Ambassador to Mexico - NARA - 302025.jpg
Zimmermann Telegram as Received by the German Ambassador to Mexico - NARA - 302025.jpg

It was a hidden message. A leader in Germany sent it to Mexico. The note asked for help in a war.

Arthur Zimmermann.png
Arthur Zimmermann.png

Germany wanted to stop the United States from helping others. They promised land to Mexico if they fought together.

British workers found the secret note. They read the hidden words. This made many people in America very angry.

This note changed the world. It helped lead the United States into the war.

96 words

During World War I, a secret message changed history.

Zimmermann Telegram as Received by the German Ambassador to Mexico - NARA - 302025.jpg
Zimmermann Telegram as Received by the German Ambassador to Mexico - NARA - 302025.jpg
This was the Zimmermann telegram. It was sent on January 17, 1917. Arthur Zimmermann was a top leader in Germany. He sent the coded note to the German ambassador in Mexico.
Arthur Zimmermann.png
Arthur Zimmermann.png

Germany wanted to stop the United States from helping its allies. The telegram proposed a military deal. Germany promised to help Mexico win back land. This land included Texas, Arizona, and New Mexico.

Zimmermann Telegram.svg
Zimmermann Telegram.svg

British intelligence workers found the message. They used a codebook to read the secret words.

Ztel2.jpg
Ztel2.jpg
When the public found out, they were very angry. Arthur Zimmermann later admitted the note was real. This helped lead the United States to declare war on Germany in April 1917. The note was a huge win for British spies. It helped decide how the war would go.

155 words

The Zimmermann telegram was a secret message that changed the course of history.

Zimmermann Telegram as Received by the German Ambassador to Mexico - NARA - 302025.jpg
Zimmermann Telegram as Received by the German Ambassador to Mexico - NARA - 302025.jpg
It was sent by the German Foreign Office on January 17, 1917. This was during World War I, a massive conflict involving many nations. The note was a coded diplomatic communication. It was meant to be a private plan between Germany and Mexico. This single piece of intelligence helped decide how the world would fight the war.
Arthur Zimmermann.png
Arthur Zimmermann.png

Germany had a specific plan for this secret note. Arthur Zimmermann was a top official in the German government. He sent the message to Heinrich von Eckardt, the German ambassador in Mexico. The plan was to offer a military alliance to Mexico. Germany promised to provide financial support to the Mexican government. In return, they wanted Mexico to join the war against the United States. This would keep American troops busy near their own borders. It would also slow down the shipment of weapons to Germany's enemies.

The Mexican Telegraph Company -- Galveston.jpg
The Mexican Telegraph Company -- Galveston.jpg

The goal of the telegram was to reclaim lost land. Germany told Mexico they could win back certain territories. These areas included Texas, Arizona, and New Mexico.

Zimmermann Telegram.svg
Zimmermann Telegram.svg
This was a very bold and risky proposal. Germany hoped this would stop the United States from helping the Allies. The German leaders believed they could win the war before the Americans arrived. They wanted to use submarine warfare to stop supplies from reaching Europe. This plan was part of a larger effort to control the war's outcome.

British intelligence workers managed to find and read the secret message.

Ztel2.jpg
Ztel2.jpg
They worked in a place called Room 40. This group of codebreakers used recovered German documents to crack the code. One way they succeeded was by using a codebook left behind by Wilhelm Wassmuss. The British were careful about when they shared the news. They waited because they did not want Germany to know their codes were broken. Eventually, the truth came out and it enraged the American people. Arthur Zimmermann even admitted the telegram was real on March 3, 1917.

Mexico had to decide if this offer was a good idea. President Venustiano Carranza sent experts to study the plan. They decided the war was unwinnable for Mexico. Mexico was already fighting its own civil war at the time. The United States had a much stronger military than Mexico. Also, the German promise of money seemed very unreliable. Mexico chose to stay neutral during the war instead. This decision helped keep the peace between the two neighbors. The United States declared war on Germany in April 1917.

Zimmermann-telegramm-offen.jpg
Zimmermann-telegramm-offen.jpg

447 words

The Zimmermann telegram was a secret diplomatic communication that altered the course of World War I. Issued by the German Foreign Office on January 17, 1917, it proposed a military alliance between the German Empire and Mexico. This message was a piece of signals intelligence, which refers to information gathered from intercepted communications. Its discovery and revelation became one of the most significant intelligence triumphs for Great Britain. The telegram's contents helped drive the United States to declare war on Germany in April 1917.

Zimmermann Telegram as Received by the German Ambassador to Mexico - NARA - 302025.jpg
Zimmermann Telegram as Received by the German Ambassador to Mexico - NARA - 302025.jpg

The message was dispatched by Arthur Zimmermann, a high-ranking civil servant in the German Foreign Office. He sent the coded telegram to Heinrich von Eckardt, the German ambassador in Mexico. Zimmermann sent this note in anticipation of Germany resuming unrestricted submarine warfare on February 1, 1917. Unrestricted submarine warfare meant German U-boats would attack all ships, including neutral ones. The telegram instructed Von Eckardt to propose a military alliance to the Mexican government if the United States entered the war.

Arthur Zimmermann.png
Arthur Zimmermann.png

Germany had several strategic motivations for this proposal. The primary goal was to prevent the United States from sending troops and war materials to the Allies. By inciting a conflict between Mexico and the United States, Germany hoped to tie down American forces on their own continent. This would slow the export of American arms to the European battlefields. The German High Command believed they could win the war on the Western Front before American forces arrived in large numbers. They intended to use submarine warfare to strangle British supply lines in the process.

The Mexican Telegraph Company -- Galveston.jpg
The Mexican Telegraph Company -- Galveston.jpg

The content of the telegram included a specific promise of land to Mexico. Germany suggested that, with German aid, Mexico could recover territories lost to the United States. These territories included Texas, New Mexico, and Arizona.

Zimmermann Telegram.svg
Zimmermann Telegram.svg
This plan was part of a longer German effort to influence Mexico. In 1915, a German officer named Franz von Rintelen had even attempted to provide $12 million to Mexico to incite war. However, the 1917 proposal was much more direct and formal in its diplomatic approach.

British intelligence successfully intercepted and decrypted the message in a specialized unit called Room 40. This group of codebreakers worked at the Admiralty. They were able to crack the German diplomatic code, known as 13040, using various methods. One breakthrough occurred after the failure of the Niedermayer–Hentig Expedition to Afghanistan. During that mission, a man named Wilhelm Wassmuss abandoned a codebook that the Allies later recovered. This helped the British understand German communications.

Ztel2.jpg
Ztel2.jpg

Despite the successful decryption, British leaders were cautious about revealing their success. William Reginald Hall, the chief of Room 40, hesitated to share the news immediately. He feared that telling the Americans would reveal that Britain had broken German codes. He also worried about exposing British eavesdropping on United States diplomatic traffic. After several weeks, cryptographers Nigel de Grey and William Montgomery completed the decryption. The truth was eventually revealed, and the news enraged the American public. Arthur Zimmermann publicly admitted the telegram was genuine on March 3, 1917.

Zimmermann-telegramm-offen.jpg
Zimmermann-telegramm-offen.jpg

Mexican President Venustiano Carranza responded by assigning a military commission to study the German proposal. The commission concluded that the war was unwinnable for Mexico. They noted that Mexico was already struggling with an internal civil war. Furthermore, the United States possessed a much stronger military than Mexico. The commission also found Germany's promises of "generous financial support" to be unreliable. Germany had previously told Carranza they could not provide enough gold for a Mexican national bank. Consequently, Mexico remained neutral during World War I.

Zimmermann-telegramm-offen.jpg
Zimmermann-telegramm-offen.jpg

615 words
🖼️ Images & Media (8)
File:Zimmermann Telegram as Received by the German Ambassador to Mexico - NARA - 302025.jpg
Zimmermann Telegram as Received by the...
File:Zimmermann Telegram.svg
Zimmermann Telegram.svg
File:Arthur Zimmermann.png
Arthur Zimmermann.png
File:The Mexican Telegraph Company -- Galveston.jpg
The Mexican Telegraph Company -- Galveston.jpg
File:Ztel2.jpg
Ztel2.jpg
File:Zimmermann-telegramm-offen.jpg
Zimmermann-telegramm-offen.jpg
File:Cartoon for a Telegram.jpg
Cartoon for a Telegram.jpg
File:Exploding in his Hands.jpg
Exploding in his Hands.jpg
Up Next
🏛️
Mexican–American War
History
More to explore

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.