The
Zimmermann Telegram (or
Zimmermann Note; ; ) was a
codedIn cryptography, a code is a method used to transform a message into an obscured form, preventing those who do not possess special information, or key, required to apply the transform from understanding what is actually transmitted. The usual method is to use a codebook with a list of common...
telegram dispatched by the Foreign Secretary of the
German EmpireThe German Empire is the name commonly used in English to describe Germany from the unification of Germany and proclamation of Wilhelm I as German Emperor on 18 January 1871 to 1918, when it became a German republic after defeat in World War I and the abdication of Wilhelm II .The term Second Reich...
,
Arthur ZimmermannArthur Zimmermann was State Secretary for Foreign Affairs of the German Empire from November 22, 1916, until his resignation on August 6, 1917. His name is associated with the Zimmermann Telegram during World War I...
, on January 16, 1917, to the
GermanGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
ambassador in Washington,
Johann von BernstorffJohann Heinrich Graf von Bernstorff was a German politician and the ambassador to the United States and Mexico from 1908 to 1917.- Early life :...
, at the height of
World War IWorld War I , also known as the First World War, the Great War, and the War to End All Wars, was a global military conflict which involved most of the world's great powers, assembled in two opposing alliances: the Triple Entente and the Triple Alliance...
. On January 19, Bernstorff, per Zimmermann's request, forwarded the Telegram to the German ambassador in
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
,
Heinrich von EckardtHeinrich von Eckardt was the ambassador for the German Empire in Mexico, assuming office around 1915 and spending most of his time as ambassador during World War I...
. Zimmermann sent the Telegram in anticipation of the resumption of unrestricted submarine warfare by the German Empire on February 1, an act which German chancellor Bethmann-Hollweg feared would draw the neutral United States into war on the side of the
AlliesThe Entente powers were the countries at war with the Central Powers during World War I. The key members of the Entente were the United Kingdom, France, and the Russian Empire. New Zealand, Belgium, Serbia, Canada, Australia, Italy, Romania and the United States were also drawn into the war...
.
The
Zimmermann Telegram (or
Zimmermann Note; ; ) was a
codedIn cryptography, a code is a method used to transform a message into an obscured form, preventing those who do not possess special information, or key, required to apply the transform from understanding what is actually transmitted. The usual method is to use a codebook with a list of common...
telegram dispatched by the Foreign Secretary of the
German EmpireThe German Empire is the name commonly used in English to describe Germany from the unification of Germany and proclamation of Wilhelm I as German Emperor on 18 January 1871 to 1918, when it became a German republic after defeat in World War I and the abdication of Wilhelm II .The term Second Reich...
,
Arthur ZimmermannArthur Zimmermann was State Secretary for Foreign Affairs of the German Empire from November 22, 1916, until his resignation on August 6, 1917. His name is associated with the Zimmermann Telegram during World War I...
, on January 16, 1917, to the
GermanGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
ambassador in Washington,
Johann von BernstorffJohann Heinrich Graf von Bernstorff was a German politician and the ambassador to the United States and Mexico from 1908 to 1917.- Early life :...
, at the height of
World War IWorld War I , also known as the First World War, the Great War, and the War to End All Wars, was a global military conflict which involved most of the world's great powers, assembled in two opposing alliances: the Triple Entente and the Triple Alliance...
. On January 19, Bernstorff, per Zimmermann's request, forwarded the Telegram to the German ambassador in
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
,
Heinrich von EckardtHeinrich von Eckardt was the ambassador for the German Empire in Mexico, assuming office around 1915 and spending most of his time as ambassador during World War I...
. Zimmermann sent the Telegram in anticipation of the resumption of unrestricted submarine warfare by the German Empire on February 1, an act which German chancellor Bethmann-Hollweg feared would draw the neutral United States into war on the side of the
AlliesThe Entente powers were the countries at war with the Central Powers during World War I. The key members of the Entente were the United Kingdom, France, and the Russian Empire. New Zealand, Belgium, Serbia, Canada, Australia, Italy, Romania and the United States were also drawn into the war...
. The Telegram instructed Ambassador Eckardt that if the United States appeared likely to enter the war he was to approach the Mexican government with a proposal for military alliance. He was to offer Mexico material aid in the reclamation of territory lost during the Mexican-American War, specifically the
American statesA U.S. state is any one of 50 federated states of the United States of America that share sovereignty with the federal government . Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile...
of
TexasTexas is the second-largest U.S. state in both area and population, and the largest state in the contiguous United States.The name had wide usage among native Americans, meaning "friends" or "allies"...
,
New MexicoNew Mexico is a state located in the southwestern region of the United States. Inhabited by Native American populations for many centuries, it has also been part of the Imperial Spanish viceroyalty of New Spain, part of Mexico, and a U.S. territory. Among U.S...
, and
ArizonaThe State of Arizona is a state located in the southwestern region of the United States. The capital and largest city is Phoenix. The second largest city is Tucson, followed in size by the four Phoenix metropolitan area cities of Mesa, Glendale, Chandler, and Scottsdale.Arizona was the 48th and...
. Eckardt was also instructed to urge Mexico to help broker an alliance between Germany and
Japanis an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
.
The Zimmermann Telegram was intercepted and decoded by the
BritishThe United Kingdom of Great Britain and Northern Ireland is a sovereign state located off the northwestern coast of continental Europe. It is an island country, spanning an archipelago including Great Britain, the northeastern part of Ireland, and many small islands...
cryptographers of
Room 40In the history of cryptography, Room 40 was the section in the Admiralty most identified with the British cryptography effort during World War I.It was formed shortly after the start of the war in October 1914...
. The revelation of its contents in the American press on March 1 caused public outrage that contributed to the United States' declaration of war against Germany and its allies on April 6.
The Telegram
Zimmermann's message was :
On the first of February, we intend to begin unrestricted submarine warfare. In spite of this, it is our intention to endeavor to keep the United States of America neutral.
In the event of this not succeeding, we propose an alliance on the following basis with Mexico: That we shall make war together and make peace together. We shall give generous financial support, and an understanding on our part that Mexico is to reconquer the lost territory in New Mexico, Texas, and Arizona. The details of settlement are left to you.
You are instructed to inform the President [of Mexico] of the above in the greatest confidence as soon as it is certain that there will be an outbreak of war with the United States and suggest that the President, on his own initiative, invite Japan to immediate adherence with this plan; at the same time, offer to mediate between Japan and ourselves.
Please call to the attention of the President that the ruthless employment of our submarines now offers the prospect of compelling England to make peace in a few months.
Mexican response
Mexican President
Venustiano CarranzaVenustiano Carranza de la Garza was one of the leaders of the Mexican Revolution. He ultimately became President of Mexico following the overthrow of the dictatorial Huerta regime in the summer of 1914 and during his administration the current constitution of Mexico was drafted...
assigned a general to assess the feasibility of a Mexican takeover of their former territories. The general concluded that it would not be possible or even desirable for the following reasons:
- Attempting to re-take the former territories would mean certain war with the United States.
- No matter how "generous" it was, Germany's "financial support" would be worthless. Mexico could not use it to acquire arms, ammunition, or other war supplies, because the United States was the only sizable arms manufacturer in the Americas. The Royal Navy
The Royal Navy of the United Kingdom is the oldest of HM Armed Forces . From the beginning of the 18th century until well into the 20th century, it was the most powerful navy in the world, playing a key part in establishing the British Empire as the dominant world power from 1815 until the early...
controlled the Atlantic sea lanes, so Germany could not possibly supply any quantity of arms.
- Even if Mexico had the military means to re-take the territory it would have had severe difficulty accommodating and/or pacifying the large English-speaking population.
- Mexico had even cooperated with the ABC nations to prevent a war with the United States, generally improving relations. If Mexico were to enter war against USA it would strain relations with ABC nations—who would later declare war on Germany.
Carranza formally declined Zimmermann's proposals on April 14, by which time the U.S. had declared war on Germany.
British interception
The Telegram was transmitted by radio and also across two telegraph routes under the cover of diplomatic messages by two neutral governments, Sweden and the United States. Germany lacked direct telegraphic access to the Western hemisphere because the British had cut the German cables in the Atlantic and shut down German stations in neutral countries. This forced Germany to use British and American cables instead despite the risk of interception. The Zimmermann messages passed over cables that touched on British soil, and as a result were intercepted there by British intelligence. President Woodrow Wilson had granted the German diplomats the privilege of sending their messages under the cover of U.S. diplomatic traffic in hopes that this would enable Germany to remain in touch with the United States and further Wilson's aims of ending the war. The message passing through this way was sent from
BerlinBerlin is the capital city and one of sixteen states of Germany. With a population of 3.4 million within its city limits, Berlin is Germany's largest city. It is the second most populous city and the eighth most populous urban area in the European Union...
to the German ambassador in
WashingtonWashington, D.C. , formally the District of Columbia and commonly referred to as Washington, the District, or simply D.C., is the capital of the United States, founded on July 16, 1790...
, Johann von Bernstorff, for re-transmission to von Eckardt in Mexico. What was a privilege provided to further peace actually brought war.
The Telegram was intercepted as soon as it was sent. The codebreakers in
Room 40In the history of cryptography, Room 40 was the section in the Admiralty most identified with the British cryptography effort during World War I.It was formed shortly after the start of the war in October 1914...
at the
AdmiraltyThe Admiralty was formerly the authority in the United Kingdom responsible for the command of the Royal Navy. Originally exercised by a single person, the office of Lord High Admiral was from the 18th century onward almost invariably put "in commission", and was exercised by a Board of Admiralty.In...
received a copy
and
decryptedCryptanalysis is the study of methods for obtaining the meaning of encrypted information, without access to the secret information which is normally required to do so. Typically, this involves knowing how the system works and finding a secret key...
enough to get the gist of it. The German Foreign Office encrypted the Telegram with cipher 0075, which Room 40 had partly broken.
The British government wanted to use the incriminating Telegram. It provided a splendid opportunity to draw the United States into World War I on the Allied side. Anti-German feeling in the United States was particularly strong at that moment, due to the German policy of "unrestricted"
submarineA submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has only limited underwater capability...
warfare.
But the British had two problems. They had to explain to the Americans how they got the ciphertext of the Telegram, without telling the Americans about the British intelligence operation monitoring neutral diplomatic traffic, and they had to have a public explanation of how they had the Telegram's deciphered text without revealing to Germany that they had broken German cypher.
The British solved the first problem by also getting the ciphertext of the Telegram from the telegraph office in Mexico. The British guessed that the German Embassy in Washington would relay the message by commercial telegraph. So the Mexican telegraph office would have the ciphertext. "Mr. H.", a British agent in Mexico, bribed an employee of the commercial telegraph company for a copy of the message. (
Sir Thomas HohlerSir Thomas Beaumont Hohler, KCMG, CB, JP was a British diplomat.During World War I, he was head of the British delegation to Mexico, in Mexico City, and was involved in the interception of the German Zimmermann Telegram that was used to promote the entry of the United States into the war...
, then British ambassador in Mexico, claims to have been Mr. H in his autobiography.) This ciphertext could be passed to the Americans without embarrassment.
The retransmission was enciphered using cipher 13040, which Britain had captured a copy of in
MesopotamiaThe Mesopotamian campaign was a campaign in the Middle Eastern theatre of the Great War fought between the Allies represented by the British Empire, mostly troops from the Indian Empire, and the Central Powers, mostly of the Ottoman Empire.- Background :...
. So by mid-February the British had the complete text.
The second problem was solved by a cover story: that the Telegram's deciphered text had been stolen in Mexico. (The U.S. was informed of the deciphering, but backed up the cover story.) The German government refused to consider a possible code break, and instead sent von Eckardt on a witch-hunt for a traitor in the embassy in Mexico.
British use of the Telegram
On February 19,
"Blinker" HallAdmiral Sir William Reginald Hall, KCMG, CB, RN was the British Director of Naval Intelligence from 1914 to 1919...
, the head of Room 40, showed the Telegram to the secretary of the U.S. Embassy in Britain, Edward Bell. Bell was at first incredulous, thinking it was a forgery, then enraged. On February 20 Hall informally sent a copy to U.S. ambassador
Walter PageWalter Hines Page was an American journalist, publisher, and diplomat. He was the United States ambassador to the United Kingdom during World War I....
. On February 23, Page met with Foreign Minister Balfour, and was given the ciphertext, the message in German, and the English translation. Then Page reported the story to President
Woodrow WilsonThomas Woodrow Wilson was the 28th President of the United States. A leading intellectual of the Progressive Era, he served as President of Princeton University from 1902 to 1910, and then as the Governor of New Jersey from 1911 to 1913...
, including details to be verified from telegraph company files in the U.S.
Effect in the United States
Popular sentiment in the United States at that time was anti-Mexican as well as anti-German, while Mexico was anti-American and in some cases, anti-European. General
John J. PershingGeneral of the Armies John Joseph Pershing, Honorary GCB; September 13, 1860 – July 15, 1948, was a general officer in the United States Army. Pershing is the only person to be promoted in his own lifetime to the highest rank ever held in the United States Army—General of the Armies General of the...
had long been chasing the revolutionary
Pancho VillaJosé Doroteo Arango Arámbula , better known as Francisco “Pancho” Villa, was the first Mexican Revolutionary general along with Troyal Gonzales and Uriel Carrasco....
, who had carried out several cross-border raids. News of the Telegram further inflamed tensions between the U.S. and Mexico.
At first, the Telegram was widely believed to be a forgery perpetrated by British intelligence. This belief, which was not restricted to pacifist and pro-German lobbies, was promoted by German and Mexican diplomats, and by some American papers, especially the
HearstWilliam Randolph Hearst was an American newspaper magnate and leading newspaper publisher.Hearst was born in San Francisco, California, to millionaire mining engineer George Hearst and Phoebe Apperson. Following preparation at St...
press empire. However, first on March 3 1917 and later on March 29 1917, Arthur Zimmermann himself admitted that the Telegram was genuine.
On February 1, Germany had resumed "unrestricted" submarine warfare, which caused many civilian deaths, including American passengers on British ships. This caused widespread anti-German sentiment. The Telegram greatly increased this feeling. Besides the highly provocative anti-U.S. proposal to Mexico, the Telegram also mentioned "ruthless employment of our submarines."
United States declares war against Germany
Wilson responded by asking Congress to arm American ships so that they could fend off potential German submarine attacks. A few days later, on April 2, 1917, Wilson asked Congress to declare war on Germany. On April 6, 1917, Congress complied, bringing the United States into World War I.
The telegram was not the only reason for the U.S. entry into the war. Previously, German
U-boatU-boat is the anglicized version of the German word , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...
s had sunk US ships or ships which carried US citizens, of which the most well known was the RMS
LusitaniaRMS Lusitania was an ocean liner owned by the Cunard Line and built by John Brown and Company of Clydebank, Scotland, torpedoed by a German U-boat on 7 May 1915. The ship sank in 18 minutes, eight miles off the Old Head of Kinsale, Ireland, killing 1,198 of the 1,959 people aboard...
, torpedoed off the coast of
IrelandIreland is the third-largest island in Europe and the twentieth-largest island in the world. It lies to the north-west of continental Europe and is surrounded by hundreds of islands and islets. To the east of Ireland, separated by the Irish Sea, is the island of Great Britain...
in May 1915. US ships sunk, less well known, were the SS
HousatonicSS Georgia was a passenger ship in the North Atlantic from 1891 to 1917.Built by Barclay, Curle & Co, Glasgow, she was a 3,143 gross ton ship, length 331ft x beam 41.1ft, with a straight stem, one funnel, two masts, a single screw and a speed of 11 knots...
in Feb 1917 in the
Bay of BiscayThe Bay of Biscay or the Cantabrian Sea is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea...
, and the SS
CaliforniaThe twin screw steamer California was built by D & W Henderson Ltd, Glasgow for the Anchor Line Ltd in 1907 as a replacement for the aging ocean liner Astoria, which had been in continuous service since 1884...
off the Irish coast. It was perceived as especially perfidious that the Telegram was sent to the German embassy in Washington via the U.S. embassy in Berlin and the U.S.-operated cable from Denmark (in fact, that was the only relatively sure channel left to the Germans to communicate to their diplomats in Mexico). Once the American public believed the Telegram to be real, it was all but inevitable that the U.S. would join the Great War.
Historical post-script
In October 2005, it was revealed that an original typescript of the deciphered Zimmermann Telegram had recently been discovered by an unnamed historian who was researching and preparing an official history of the United Kingdom’s
Government Communications HeadquartersThe Government Communications Headquarters is a British intelligence agency responsible for providing signals intelligence and information assurance to the UK government and armed forces...
(GCHQ). The document is believed to be the actual telegram shown to the American ambassador in London in 1917. Marked in Admiral Hall's handwriting at the top of the document are the words: "This is the one handed to Dr Page and exposed by the President." Since many of the secret documents in this incident had been destroyed, it had previously been assumed that the original typed "decrypt" was gone forever. However, after discovery of this document, the GCHQ official historian said: "I believe that this is indeed the same document that Balfour handed to Page."
External links