American Neutrality in the Early Years
When war broke out in Europe in 1914, the United States took a position of neutrality, or a position of not supporting either side in a conflict. This position was supported by most Americans, many of whom were recent immigrants from European countries. The vast geographical distance between Europe and the United States allowed those Americans who were not recent immigrants to feel removed from the conflict. In August 1914 President Woodrow Wilson, the 28th president of the United States, delivered a declaration of neutrality to Congress. In his speech, he asked that Americans remain "impartial in thought, as well as action" to avoid signaling a preference for one side over the other in the war.
Over the next three years, Wilson would struggle to maintain neutrality in the face of the escalating conflict in Europe. The United States was currently in an economic recession. As the demand for goods caused by the war escalated in Europe, American manufacturers and farmers were eager to step up and provide much-needed supplies. The United States exported to countries that were part of both the Central Powers and Allied alliances, but already-established trade practices favored the Allied nations. In addition, American banks loaned money to nations on both sides of the conflict despite warnings from the secretary of state that these loans would be a violation of neutrality.
Deterioration of U.S. Relations with Germany

On January 22, 1917, Wilson made another speech asking for "peace without victory." Great Britain privately expressed a willingness to enter negotiations to end the war, but Germany had resolved on January 9 to engage in unrestricted submarine warfare, a military tactic in which submarines fire upon marine vessels without warning with the objective of sinking them. Germany announced these intentions on February 1, 1917, and on February 3, 1917, the United States officially terminated diplomatic dealings with Germany. At the end of February Wilson asked Congress to permit the armament of U.S. marine vessels to protect them from German attack.
Zimmermann Telegram
By the beginning of 1917, the Allied forces in Europe were anxious for the United States to actively participate in the war. The Allied forces were better equipped than the Central Powers in terms of soldiers and supplies, but the German army had a solid hold in France and Russia. The war was at a stalemate—in a situation in which neither side had the opportunity to advance.
In January 1917 German foreign secretary Arthur Zimmermann sent an encrypted telegram to the German ambassador in Mexico City, Heinrich von Eckardt. The telegram, which would become known as the Zimmermann Telegram, instructed von Eckardt to propose an alliance between Mexico and Germany. Germany knew that because of their reinstatement of unrestricted submarine warfare it was only a matter of time before the United States joined in the war. Germany proposed that Mexico enter the war on the side of the Central Powers and lead a ground invasion of the United States, who was anticipated to enter the war on the side of the Allies. In turn, Germany would help Mexico regain territory yielded to the United States in the aftermath of the Mexican-American War—Texas, New Mexico, and Arizona. The telegram also instructed the Mexican president to invite Japan to join their alliance.
The telegram was sent to von Eckardt via the German ambassador in Washington, D.C., and was intercepted by British intelligence. British intelligence officers were able to decode the telegram and forwarded a transcript of the decoded and translated telegram to President Woodrow Wilson. On March 1, 1917, the message was published for the American public:
Berlin. January 19, 1917.Americans were sufficiently convinced that German hostility toward the United States posed an imminent threat, and Wilson declared war on Germany five weeks later with the support of the American people.
On the first of February we intend to begin submarine warfare unrestricted. In spite of this it is our intention to endeavor to keep neutral the United States of America.
If this attempt is not successful we propose an alliance on the following basis with Mexico: That we shall make war together and together make peace. We shall give generous financial support and it is understood that Mexico is to reconquer the lost territory in New Mexico, Texas and Arizona. The details are left to you for settlement.
You are instructed to inform the President of Mexico of the above in the greatest confidence as soon as it is certain there will be an outbreak of war with the United States and suggest that the President of Mexico on his own initiative should communicate with Japan suggesting adherence at once to this plan; at the same time offer to mediate between Germany and Japan.
Please call to the attention of the President of Mexico that the employment of ruthless submarine warfare now promises to compel England to make peace in a few months. (Signed) ZIMMERMANN.
—”Documentary Proof of Teuton Plan to Embroil America with Southern Republic, Offering Southwestern States as Bribe, in Hands of This Government,” The Sun, New York, NY, March 1, 1917, p. 1
