10.5The road to war

Through the 1930s, most Americans wanted no part of the world's mounting crises, and Congress passed Neutrality Acts to keep the nation out of foreign wars. But aggression spread: Japan invaded China, and Nazi Germany, under Adolf Hitler, conquered much of Europe by 1940.

Roosevelt gradually moved to aid the Allies, notably through Lend-Lease, which supplied Britain and later the Soviet Union. Isolationists resisted fiercely. The debate ended abruptly on December 7, 1941, when Japan attacked the U.S. naval base at Pearl Harbor. The United States declared war, entering a global conflict that would demand total national mobilization.