Why Did America Enter the First World War?

History Hit Podcast with Michael Neiberg

4 mins

12 Sep 2018

This article is an edited transcript of America’s Entry into the First World War – Michael Neiberg on Dan Snow’s History Hit, first broadcast 3 April 2017. You can listen to the full episode below or to the full podcast for free on Acast.

Between 1914 and 1917, America was focussed on protecting its interests and keeping out of the war for as long as possible. Americans knew how awful the Western Front was, they knew the risks of becoming involved. But by the spring of 1917 the picture had changed drastically.

What changed?

America’s entry into the war was influenced both by strategic and moral considerations, as well as the impact the war was having on the country itself.

By the spring of 1917, Americans were beginning to conclude that neutrality had made them less safe, not more so. If Germany won the war, most Americans expected that part of the peace deal would include the transfer of territory from Canada, the Caribbean, and other British and French possessions in the Western Hemisphere to Germany. That’s why the United States bought the Danish Virgin Islands from Denmark in March 1917, in order to keep them out of German hands.

… the US had actually put itself in a very dangerous strategic position by staying neutral.

By the spring of 1917, there was a sense that Germany posed a real threat to the United States. Germany’s resumption of unrestricted submarine warfare, and the famous Zimmermann Telegram, convinced the last doubters that the US had actually put itself in a very dangerous strategic position by staying neutral.

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A pro-German America?

There is a clear sense from the earliest days of the war that the vast majority of Americans believed the Allies should win. The perception was that Germany had taken a rather minor diplomatic crisis in the Balkans and turned it into a war the likes of which the world had never seen. They observed that Britain and France were fighting an essentially defensive war. Those Americans who did not agree with that position wanted the United States to remain neutral and stay out of the war completely.

It seems that there was very little pro-German sentiment, despite the large section of the American population with German heritage. What pro-German sentiment there was had virtually vanished by the time of the Lusitania. A German-American professor at Harvard, Hugo Münsterberg, very eloquently defended Germany’s position in the early years of the war. But he stopped after the sinking of the Lusitania, in large part because he realised he wasn’t in line with the mood of the American people.

Part of the encrypted Zimmermann Telegram

Two critical events

Two major events in 1917 contributed to a change of heart in America.

First came the Zimmermann Telegram, which was made public in February, 1917. The Zimmermann Telegram was sent by the German Foreign Minister to Germany’s representative in Mexico proposing an alliance between the two countries. For the American people, the telegram confirmed the fears that Germany was trying to build an international alliance aimed at the United States. Some believed this was a crazy theory, supported only by nationalists like Theodore Roosevelt. However, once they saw the Zimmermann Telegram, they could no longer  deny that this was a threat.

The publication of the telegram also meant support for the war spread out from the East Coast to the rest of the country. The Zimmermann Telegram had placed the American South and West directly in the crosshairs. The war was no longer about Belgium and the atrocities there. It was about their own backyard.

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The second event that made a big impression was the German resumption of unrestricted submarine warfare.

Germany was sinking shipping in the Atlantic carrying American nationals. This posed a difficult question for the Americans and they disagreed about what to do. In 1915, when Germany first embarked on unrestricted submarine warfare, there was a great debate. President Wilson’s secretary of state resigned because he thought the United States should just ban Americans from traveling if the risk was out there. Those, like Theodore Roosevelt, on the right believed the US should cut diplomatic relations with a country behaving in this way. President Wilson himself favoured a middle course, and pursued a diplomatic solution.

President Wilson addressing Congress

The final decision

The American people were well in front of Wilson. If Wilson had not declared war, the American people would have demanded that the senate do it.  It is the senate after all, not the president, that declares war.

The American people were getting ready for this war with or without Wilson’s direction.

Essentially, Wilson had run out of options. His diplomacy was done. He had a meeting with his cabinet and most of his officials told him it was time for war. Two privately planned to resign if Wilson didn’t declare war. Wilson didn’t tell them what he had decided. He merely said something along the lines of: “Thank you, gentlemen, for your advice.” And he walked out of the room.

The American people were getting ready for this war with or without Wilson’s direction. Any examination of Wilson’s actions must go alongside a study of the evolution of the mood of the country and how it changed from the end of 1916 to April of 1917.