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World War II (1939-45) grew out of a quest for power and territory in both Europe and Asia. On the European front, the war was sparked by the land-grabbing maneuvers of German dictator Adolf Hitler and his National Socialist German Workers' Party (or Nazi Party for short). (A dictator is a leader of a government in which absolute—and often unfair and oppressive—power is held by one ruler alone. In Germany's case, that leader was Hitler.)

Germany had been in a state of political and economic turmoil since its devastating loss to opposing forces in World War I (1914-18). In an attempt to restore the nation's former glory and expand German influence across Europe, Hitler launched an invasion of neighboring Poland on September 1, 1939. Great Britain and France responded with a show of solidarity (fellowship or unity), declaring war on Germany two days later. The Germans followed up with an attack on Belgium, the Netherlands, Luxembourg, and France in the spring of 1940.

The inspiring words of British prime minister Winston Churchill held Great Britain together as the prospect of a full-scale war in Europe became a reality. In his "Blood, Toil, Tears and Sweat" speech, his "Be Ye Men of Valour" speech, and his "Finest Hour" speech—all delivered in the spring of 1940—Churchill calls for total commitment to the war effort and an ultimate victory over Hitler's forces, "however long and hard the road may be."

Germany, Italy, and Japan had joined forces as the Axis Powers in September of 1940. The forces that fought against Germany—including France, Britain, and later the Soviet Union and the United States—were known as the Allied Powers. In the summer of 1941, as the threat to democracy (government by the people) escalated worldwide, U.S. president Franklin D. Roosevelt met with Churchill to discuss future war plans. From this meeting came the Atlantic Charter, a joint declaration by Roosevelt and Churchill that stressed the importance of human rights and charted a course for peace.

Around the same time, Germany and the Soviet Union became embroiled in armed conflict. Germany's relationship with the Soviet Union had deteriorated rapidly during 1940. Soviet leader Joseph Stalin's desires to further Soviet expansion in central Europe alarmed Hitler. He came to view Stalin—his former ally—as an obstacle to Germany's territorial growth. On June 22, 1941, more than three million German troops invaded the Soviet Union. Adolf Hitler's Order of the Day to the German Troops on the Eastern Front, issued October 2, 1941, vividly illustrates Hitler's menacing and manipulative nature.

World War II was fought on land, in the air, and on the high seas. German attempts to cut off British supply lines in the Atlantic Ocean fueled the brutal six-year-long Battle of the Atlantic. The key to Germany's early dominance in this battle was the German navy's use of U-boats, or submarines. U-boat commander Herbert A. Werner, a veteran of the war in the Atlantic, offers compelling insights from the German perspective in his memoir Iron Coffins: A Personal Account of the German U-Boat Battles of World War II .

U.S. attempts to remain neutral in the growing global conflict came to an end on December 7, 1941, when Japanese forces launched a surprise and unprovoked attack on American naval bases at Pearl Harbor, Hawaii. Japanese attacks on the Philippines, Guam, and Wake Island followed shortly after the raid on Pearl Harbor. President Roosevelt delivered his war message, better known as his "Day of Infamy" speech, to the U.S. Congress the next morning. In his speech he requested that an official congressional declaration of war be made against the Japanese Empire. "We are now in this war," Roosevelt stated in a later radio address to the nation. "We are all in it—all the way."

Winston Churchill … 5

Winston Churchill and Franklin D. Roosevelt … 21

Adolf Hitler … 31

Herbert A. Werner … 43

Franklin D. Roosevelt … 59

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