The primary reason the United States decided to enter World War 1 was the aggressive and indiscriminate submarine warfare, initiated by Germany. After the sinking of the RMS Lusitania in 1915, the death of 128 American civilians, and Germany’s refusal to stop the attacks, President Woodrow Wilson warned that the US might enter the war if Germany continued its unrestricted submarine campaign.
Zimmerman Telegram
Another significant factor was the interception and decryption of the Zimmermann Telegram. This secret message from Germany to Mexico proposed an alliance between the two nations against the United States. The proposal involved offering Mexico US territories as an incentive to join forces against the US. Once the British shared this information with the Americans, the public outcry and outrage pushed the US further toward entering the war.
Influence of Public Sentiment
By 1917, public opinion in the United States had shifted towards supporting intervention in World War 1. The influential and emotional coverage of the war by American journalists, the sinking of unarmed passenger and merchant ships, the Zimmerman Telegram, as well as the ongoing atrocities in Europe, cultivated a sense of moral obligation among Americans. The public saw Germany’s actions as violations of international law and basic humanity, which intensified calls for intervention.
Economic Pressure and Allied Debt
The US had extensive trade connections with the Allied powers (Britain, France, and Russia), while also maintaining financial ties with Germany. Due to the heavy involvement of American banks in loans to the Allies, the US risked significant financial losses if they lost the war. In contrast, joining the Allies would strengthen the chances of recovering these debts and protecting American economic interests. The war was seen as an opportunity to secure America's economic dominance in the post-war world.
Defense of Democracy and Self-Determination
Beyond self-interest, the United States also felt a moral and ideological responsibility to defend democracy and the principle of self-determination. The American public saw Germany’s actions as a threat to these ideals and believed that the US had a duty to support the values and institutions that aligned with its own.
Wilson's Fourteen Points
President Woodrow Wilson laid out his vision for a post-war peace in his famous Fourteen Points speech. These points aimed to establish a world order based on justice, collective security, and the right to self-determination. The war also allowed the US to assert its influence in shaping the global political landscape and the future peace settlement.
In conclusion, the US entered World War 1 largely due to Germany’s unrestricted submarine warfare, the interception of the Zimmermann Telegram, a shifting public opinion, economic considerations, and a desire to defend democracy and self-determination. President Woodrow Wilson’s Fourteen Points further outlined the US’s goals and vision for a post-war world order.