The United States Enters World War II | Facing History & Ourselves

The United States Enters World War II

Examine the history of the United States' entrance into World War II following the attack on Pearl Harbor.
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At a Glance

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English — US


  • History
  • The Holocaust

While the Nazis took control of Germany and planned for war in Europe, Japan aggressively expanded its control of territory in east Asia by invading Manchuria in 1931 and China in 1937. In 1940, Japan signed the Tripartite Pact with Germany and Italy, creating World War II’s Axis powers. While the United States had remained neutral in the war, it responded to Japan’s aggression in Asia with economic sanctions that caused severe shortages of natural resources that the Japanese needed for their war effort. In an attempt to prevent American interference in the Pacific war, Japan bombed Pearl Harbor, the US naval station in Hawaii, in a surprise attack on December 7, 1941. 1

On December 8, Joseph Goebbels described Adolf Hitler as “exceptionally happy” when he learned the news. Goebbels wrote:

On the basis of the Tripartite Pact we will probably not [be able to avoid] a declaration of war on the United States. But now this isn’t so bad anymore. We are now to a certain extent protected on our flanks. The United States will probably no longer make aircraft, weapons, and transport available to England so carelessly, as it can be assumed that they will need these for their own war against Japan. 2

On December 9, 1941—two days after the attack—US President Franklin D. Roosevelt addressed the American people on the radio. He said, in part:

The course that Japan has followed for the past ten years in Asia has paralleled the course of Hitler and Mussolini in Europe and in Africa. Today, it has become far more than a parallel. It is actual collaboration so well calculated that all the continents of the world, and all the oceans, are now considered by the Axis strategists as one gigantic battlefield. . . .

In these past few years—and, most violently, in the past three days—we have learned a terrible lesson.

It is our obligation to our dead—it is our sacred obligation to their children and to our children—that we must never forget what we have learned.

And what we all have learned is this: There is no such thing as security for any Nation—or any individual—in a world ruled by the principles of gangsterism. . . .

We are now in the midst of a war, not for conquest, not for vengeance, but for a world in which this Nation, and all that this Nation represents, will be safe for our children. We expect to eliminate the danger from Japan, but it would serve us ill if we accomplished that and found that the rest of the world was dominated by Hitler and Mussolini.

We are going to win the war and we are going to win the peace that follows. . . . 3

Two days later, on December 11, 1941, Adolf Hitler declared war on the United States, and Benito Mussolini of Italy followed suit. Hours later, the United States declared war on both countries. In his address to the Reichstag, Hitler said: “If it is the will of Providence that the German people not be spared this struggle, then I will be grateful to Providence for having appointed me leader in a historic contest, which for the next five hundred or one thousand years, will decisively affect not only German history but also the history of Europe, and indeed all of mankind.” 4

Connection Questions

  1. Why was Hitler happy that the Japanese bombed Pearl Harbor? How did the bombing of Pearl Harbor lead to the entry of the United States into a war against Germany?
  2. What is “gangsterism”? Why do you think Roosevelt compared the Germans to gangsters?
  3. According to Roosevelt, what principles was the United States fighting for? How did the country’s reasons for fighting the war, as articulated by Roosevelt, differ from those of Germany?
  • 1United States Holocaust Memorial Museum, “World War II in the Pacific,” last modified July 2, 2016, accessed July 6, 2016.
  • 2Joseph Goebbels, Die Tagebücher, ed. Elke Fröhlich, pt. 11, vol. 2 (K. G. Saur), 497–99, trans. Rod Stackelberg, in The Nazi Germany Sourcebook, ed. Roderick Stackelberg and Sally A. Winkle (London: Routledge, 2002), 292.
  • 3Franklin D. Roosevelt, “Fireside Chat, December 9, 1941,” The American Presidency Project, accessed May 31, 2016.
  • 4Quoted in Max von der Grün, Howl Like the Wolves: Growing Up in Nazi Germany, trans. Jan van Heurck (New York: William Morrow, 1980), 208–09.

How to Cite This Reading

Facing History & Ourselves, "The United States Enters World War II," last updated August 2, 2016.

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