The telegram suggested that Mexico could regain its "lost territory" in the American Southwest with German support, and urged Mexico to encourage Japan to join the alliance.
The British intercepted and decoded the telegram and passed the information to the United States, which caused outrage and increased support for entering the war on the side of the Allies.
Here are some of the reasons why the Zimmerman telegram was so important:
- It was a clear indication of Germany's intent to involve Mexico in the war against the United States. This was seen as a direct threat to American security, as it would have opened up a second front for the United States to fight on.
- The telegram revealed that Germany was willing to make promises of territorial gains to Mexico in order to secure its alliance. This was seen as a cynical attempt to exploit Mexican nationalism and resentment of the United States.
- The telegram provided the United States with a propaganda victory, as it helped to rally public opinion in favor of entering the war on the side of the Allies. The American public was outraged by Germany's attempt to involve Mexico in the war, and this helped to crystallize support for intervention.
- The Zimmerman telegram was a turning point in the United States' relationship with Germany, and it ultimately led to the United States' entry into World War I on the side of the Allies.