The decrypting of the Zimmermann telegram exposed Germany’s plot to encourage Mexico to attack the United States in exchange for recovering the states of Arizona, New Mexico, and Texas in the case of German victory in the First World War. This threat to American territorial integrity and to the basic values of freedom and democracy enflamed public opinion in the U.S.A. In spite of his pacifism and strong defense of American neutrality, President Woodrow Wilson was obliged to declare war against Germany.
