MIGHTY HISTORY

How Western Union helped the US enter World War I

At the height of World War I, British intelligence provided the United States with a secret telegram sent from German Foreign Secretary Arthur Zimmerman to the government of Mexico. The telegram promised the Mexicans a military alliance if the United States entered the war against Germany. The Germans promised Mexico it would help them recover the American territories of Texas, Arizona, and New Mexico it lost in the Mexican-American War.

The interception of the telegram was one of the earliest big wins for signals intelligence. Maybe the Kaiser shouldn't have sent it via Western Union.


"Hopefully no one breaks this code STOP It would mean we lose the war STOP We're paying by the word STOP"

The note from Zimmerman was sent to the German ambassador to Mexico, Heinrich von Eckardt, letting him know that the German high command intended to resume its policy of unrestricted submarine warfare in the coming days. This strategy, while effective at keeping the British Isles from getting its necessary supplies also had the adverse effect of killing innocent civilians from neutral countries – countries like the United States.

On May 7, 1915, this policy resulted in the sinking of the luxury liner RMS Lusitania, killing some 1,128 people. And 128 of those people were American civilians bound for England. The incident was illegal under international law and sparked widespread anti-German outrage in the U.S. You know relations are strained when Americans rename their food to sound less German.

"Sauerkraut" is still "Liberty Cabbage" to me.

The note read:

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.
Signed, ZIMMERMANN

This wasn't even the first time the Germans tried to incite the Mexicans against the U.S. There were at least five other occasions when the German Empire funded or assisted efforts to create tensions in North America. President Wilson even had to send U.S. troops to occupy Veracruz during his administration. What the Germans didn't take into account was the fact that Mexico was already in the middle of its own civil war, Mexico didn't stand a chance against the U.S., even then, there was already a peace agreement in place, and Mexico knew Germany couldn't actually support it in any meaningful way.

"Mexico: We are with you. But not like... there. We have to be here. But good luck in your war with the US."

The British sent the telegram to the U.S. Ambassador to Britain, who eventually got it to President Wilson. Wilson promptly gave it to the American media. When delivered to the American people, who were already anti-Mexican and anti-German, the result was explosive. To make matters worse, Zimmerman admitted the telegram was genuine in a speech to the Reichstag, and the Germans soon sunk two American merchant ships with u-boats. Three months later, in the face of American public opinion, Wilson asked Congress for a declaration of war.