Germany and Italy Declare War on the United States

By declaring war on the United States, Adolf Hitler and Benito Mussolini transformed previously separate Pacific and European conflicts into one global war.

Summary of Event

On December 11, 1941, four days after the Japanese attack on Pearl Harbor, the governments of Germany and Italy issued declarations of war against the United States. Although both the Germans and the Italians had pledged Japan their aid in the event of a conflict between Japan and the United States, their declarations cited President Franklin D. Roosevelt’s anti-Axis attitude and hostile U.S. actions as reasons for their decision to declare war. In response, the U.S. Congress passed two joint resolutions affirming a state of war against Germany and Italy. With these events, the war in Europe and the war in the Far East merged to become World War II. [kw]Germany and Italy Declare War on the United States (Dec. 11, 1941)
[kw]Italy Declare War on the United States, Germany and (Dec. 11, 1941)
[kw]War on the United States, Germany and Italy Declare (Dec. 11, 1941)
[kw]United States, Germany and Italy Declare War on the (Dec. 11, 1941)
World War II (1939-1945)[World War 02];European theater
World War II (1939-1945)[World War 02];U.S. entry
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World War II (1939-1945)[World War 02];European theater
World War II (1939-1945)[World War 02];U.S. entry
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[g]Europe;Dec. 11, 1941: Germany and Italy Declare War on the United States[00390]
[g]Germany;Dec. 11, 1941: Germany and Italy Declare War on the United States[00390]
[g]Italy;Dec. 11, 1941: Germany and Italy Declare War on the United States[00390]
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[c]Wars, uprisings, and civil unrest;Dec. 11, 1941: Germany and Italy Declare War on the United States[00390]
Hitler, Adolf
[p]Hitler, Adolf;declaration of war on the United States
Mussolini, Benito
Roosevelt, Franklin D.
[p]Roosevelt, Franklin D.;prewar foreign policy

That the United States would become involved in a war in Europe seemed highly unlikely from 1936 to 1940, because during these years, the U.S. government and people were strongly isolationist Isolationism, U.S. . Moreover, Nazi Germany was preoccupied in Europe and not primarily interested in the Western Hemisphere. Although most Americans were opposed to Benito Mussolini’s invasion of Ethiopia, the U.S. government did no more in response than invoke the first Neutrality Act (1935) Neutrality Act (1935) , which included an arms embargo designed to weaken Italy.

By 1936, it became clear that Germany and Italy were bent on territorial revisions. The Rome-Berlin Axis was formed in 1936, and Japan joined Germany and Italy in the Anti-Comintern Pact in 1937. In response, the United States government extended the Neutrality Act in 1937.

Despite their desire to stay out of war, President Roosevelt and his advisers grew increasingly concerned about the dangers of foreign aggression and human rights violations in both Europe and the Far East during the last years of the 1930’s. In November, 1938, Roosevelt responded to the German riots against Jews during Kristallnacht Kristallnacht (“night of broken glass”) by replacing the U.S. ambassador in Berlin with a chargé d’affaires; in April, 1939, the president sent letters to Adolf Hitler and Mussolini asking for assurances that they would refrain from aggression and suggesting discussions on armament reductions. Hitler’s invasion of Poland on September 1, 1939, increased the Roosevelt administration’s belief that Germany posed a real threat to U.S. security.

The year 1940 marked a turning point in U.S. foreign policy. The fall of France seriously alerted people in the United States to the might of Nazi Germany, while England’s dogged resistance to Hitler, exemplified in the Battle of Britain, resulted in increased U.S. aid to the English. During the last six months of 1940, the United States responded to the Nazi Blitzkrieg in Europe with billions of dollars for defense, destroyers for England, and the first peacetime Selective Service Act in U.S. history. In addition, Roosevelt, after winning an unprecedented third term in office in November, 1940, proclaimed the United States “the great arsenal of democracy” and announced his intention to secure congressional approval of a Lend-Lease Act to aid all countries fighting to preserve freedom.

During 1941, the United States inched ever closer to war with Germany. In January, the Joint Chiefs of Staff of the U.S. armed forces met with their British counterparts and discussed how to coordinate military actions in the event of U.S. entry into the war. It was decided that the defeat of Germany should be given top priority. On March 11, the United States Congress passed the Lend-Lease Act Lend-Lease Act (1941)[Lend Lease Act] , authorizing Roosevelt to provide arms, equipment, and supplies to “any country whose defense the President deems vital to the defense of the United States.”

In a speech on May 27, Roosevelt stressed the German danger to the Western Hemisphere and declared a state of national emergency. In August, Roosevelt and British prime minister Winston Churchill issued the Atlantic Charter against the Axis Powers. Serious naval incidents occurred in September and October, when German submarines torpedoed the U.S. destroyer Greer and sank the Reuben James. In November, the president extended lend-lease to the Soviet Union, which had been attacked by Germany on June 22, while Congress modified the Neutrality Act Neutrality Act Amendments (1941) to permit the arming of U.S. merchant ships. It is clear that by the fall of 1941, Roosevelt believed Germany was bent on world domination and was a great threat to the Western Hemisphere, and that war was a strong possibility.

In spite of the increased U.S. presence in the European conflict, the ultimate initiative for war lay with Germany and its ally Japan. By 1941, Hitler, who had first mentioned the possibility of a conflict with the United States in his 1928 unpublished sequel to Mein Kampf (1925-1926; English translation, 1939), clearly intended to wage war against the United States at some undetermined point in the future. Hitler believed the United States was culturally and racially decadent and underestimated its industrial capacity and willingness and ability to fight a war. In this connection, he was impressed by the strength of U.S. isolationism. Thus, unlike many German diplomats, Hitler failed to grasp the implications of U.S. power. Hitler’s contempt for the United States turned to hostility when Roosevelt expressed his opposition to Nazi totalitarianism and aided Great Britain and the Soviet Union.

Despite Hitler’s intention to fight, Germany developed no military plans. The Nazi dictator wanted to postpone war with Washington until Germany could construct a navy large enough to win what would certainly be a naval conflict. Consequently, Hitler ordered the German navy to avoid any incidents with U.S. ships in the Atlantic that might bring on war sooner than desired. Nevertheless, incidents did occur, the result being that an undeclared, limited naval war between the United States and Germany existed by the autumn of 1941.

Germany’s caution in the Atlantic was offset by its reckless support of Japanese ambitions in the Far East. Hoping that the Japanese would exacerbate Great Britain’s already difficult position and help check the United States’ commitment to Europe, Hitler began in 1940 to urge Tokyo to expand into Southeast Asia. To encourage the Japanese, the Nazi dictator and Mussolini entered into a defense mutual assistance agreement, the Tripartite Pact Tripartite Pact (1940) , with Japan on September 27, 1940. Six months later, on April 4, 1941, the Nazi dictator went further, assuring Japan of his full support in the event of a Japanese-American war, no matter who was the aggressor.

The Japanese attack on Pearl Harbor on December 7, 1941, came as a pleasant surprise to both Hitler and Mussolini. Believing that Japan would weaken the British, Soviet, and U.S. war efforts, the Nazi dictator decided the time had come for war with the United States. Hitler took the initiative for this conflict, ordering all-out submarine attacks on U.S. ships and, along with his Italian ally, declaring war on the United States.


In declaring war on the United States at a time when Axis military forces found themselves bogged down in the Soviet Union and under attack by the British in North Africa, Hitler and Mussolini may have made the most fatal blunder of their careers. When the Nazi dictator said that his declaration of war on the United States would be “decisive not only for the history of Germany, but for the whole of Europe and indeed for the world,” he was right. With their declaration of war, Germany and Italy not only unleashed a global conflict but also went a long way toward guaranteeing their own ultimate defeat and the postwar superpower ascendancy of the United States, which by most measures of national power except troops at arms was already the world’s most powerful country in potential. It was truly a sleeping giant, whose war-making capacity would be realized in World War II and demonstrated repeatedly in subsequent years. World War II (1939-1945)[World War 02];European theater
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Further Reading

  • Hearden, Patrick J. Roosevelt Confronts Hitler: America’s Entry into World War II. De Kalb: Northern Illinois University Press, 1987. While admitting that Roosevelt opposed the Nazi regime for both economic and ideological reasons, argues that the United States and Hitler’s Germany were primarily economic rivals.
  • Heinrichs, Waldo. Threshold of War: Franklin D. Roosevelt and American Entry into World War II. New York: Oxford University Press, 1988. Focusing on the period from March to December, 1941, shows how strategic and operational considerations helped transform Roosevelt’s policy toward Nazi Germany from neutrality to belligerence.
  • Herzstein, Robert E. Roosevelt and Hitler: Prelude to War. New York: Paragon House, 1989. Traces Roosevelt’s evolution into the “most purposeful and consequential anti-Nazi leader of his time.”
  • Jäckel, Eberhard. “Hitler Challenges America.” In Hitler in History. Hanover, N.H.: University Press of New England, 1984. Argues that Hitler’s declaration of war on the United States was motivated by a desire to guarantee that Japan would not make a separate peace.
  • Leitz, Christian. Nazi Foreign Policy, 1933-1941: The Road to Global War. New York: Routledge, 2004. Details Hitler’s foreign policy up to the declaration of war on the United States, including his alliances with Italy and Japan. Bibliographic references and index.
  • Weinberg, Gerhard L. “From Confrontation to Cooperation: Germany and the United States, 1917-1949.” In Germany, Hitler, and World War II: Essays in Modern German and World History. New York: Cambridge University Press, 1995. Argues that Hitler saw Japan’s attack on Pearl Harbor as the perfect time to begin a war he believed Germany would have to fight sooner or later.
  • _______. “The World Turned Upside Down” and “The Expanding Conflict, 1940-1941.” In A World at Arms: A Global History of World War II. New York: Cambridge University Press, 1994. Establishes the strategic context of Hitler’s declaration of war by discussing and explaining Germany’s efforts, in 1940 and 1941, to persuade Japan to expand into Southeast Asia.

World War II: Pacific Theater

World War II: European Theater

Roosevelt Signs the Lend-Lease Act

Bombing of Pearl Harbor