History of The United States - World War II

World War II

Further information: World War II and United States home front during World War II

In the Depression years the United States remained focused on domestic concerns while democracy declined across the world and many countries fell under the control of dictators. Imperial Japan asserted dominance in East Asia and in the Pacific. Nazi Germany and Fascist Italy militarized to and threatened conquests, while Britain and France attempted appeasement to avert another war in Europe. U.S. legislation in the Neutrality Acts sought to avoid foreign conflicts; however policy clashed with increasing anti-Nazi feelings following the German invasion of Poland in September 1939 that started World War II. Roosevelt positioned the U.S. as the "Arsenal of Democracy" pledging full-scale financial and munitions support for the Allies—but no soldiers. Japan tried to neutralize America's power in the Pacific by attacking Pearl Harbor on December 7, 1941, which catalyzed American support to enter the war and seek revenge.

The main contributions of the U.S. to the Allied war effort comprised money, industrial output, food, petroleum, technological innovation, and (especially 1944–45), soldiers. Much of the focus in Washington was maximizing the economic output of the nation. The overall result was a dramatic increase in GDP, the export of vast quantities of supplies to the Allies and to American forces overseas, the end of unemployment, and a rise in civilian consumption even as 40% of the GDP went to the war effort. This was achieved by tens of millions of workers moving from low-productivity occupations to high efficiency jobs, improvements in productivity through better technology and management, and the move into the active labor force of students, retired people, housewives, and the unemployed, and an increase in hours worked. It was exhausting; leisure activities declined sharply. People tolerated the extra work because of patriotism, the pay, and the confidence it was only "for the duration" and life would return to normal as soon as the war was won. Most durable goods became unavailable, and meat, clothing, and gasoline were tightly rationed. In industrial areas housing was in short supply as people doubled up and lived in cramped quarters. Prices and wages were controlled, and Americans saved a high portion of their incomes, which led to renewed growth after the war instead of a return to depression.

The Allies—the U.S., Britain and the Soviet Union, as well as China, Canada and other countries—fought the Axis powers of Germany, Italy, and Japan. The Allies saw Germany as the main threat, and gave highest priority to Europe. The U.S. dominated the war against Japan, and stopped Japanese expansion in the Pacific in 1942. After losing to the Japanese Pearl Harbor and in the Philippines, and drawing the Battle of the Coral Sea (May 1942), the American Navy inflicted a decisive blow at Midway (June 1942). American ground forces assisted in the North African Campaign that eventually concluded with the collapse of Mussolini's fascist government in 1943, as Italy switched to the Allied side. A more significant European front was opened on D-Day, June 6, 1944, in which American and Allied forces invaded Nazi-occupied France from Britain.

On the home front, mobilization of the U.S. economy was managed by Roosevelt's War Production Board. The wartime production boom led to full employment, wiping out this vestige of the Great Depression. Indeed, labor shortages encouraged industry to look for new sources of workers, finding new roles for women and blacks.

However the fervor also inspired anti-Japanese sentiment, which responded by removing everyone of Japanese descent from the West Coast war zone. Research and development took flight as well, best seen in the Manhattan Project, a secret effort to harness nuclear fission to produce highly destructive atomic bombs.

The Allied pushed the Germans out of France, but faced an unexpected counterattack at the Battle of the Bulge in December. The final German effort failed, and as 1945 opened Allied armies in East and West were converging on Berlin, as the Nazis hurriedly tried to kill the last remaining Jews. The western front stopped short, leaving Berlin to the Soviets as the Nazi regime formally capitulated in May 1945, ending the war in Europe. Over in the Pacific, the U.S. implemented an island hopping strategy toward Tokyo, establishing airfields for bombing runs against mainland Japan from the Mariana Islands and achieving hard-fought victories at Iwo Jima and Okinawa in 1945. Bloodied at Okinawa, the U.S. prepared to invade Japan's home islands when B-29's dropped two atomic bombs on Japanese cities, forcing the empire's surrender in a matter of days and thus ending World War II. The U.S. occupied Japan (and part of Germany), sending Douglas MacArthur to restructure the Japanese economy and political system along American lines.

Though the nation lost more than 400,000 soldiers, the mainland prospered untouched by the devastation of war that inflicted a heavy toll on Europe and Asia.

Participation in postwar foreign affairs marked the end of predominant American isolationism. The awesome threat of nuclear weapons inspired both optimism and fear. Nuclear weapons were never used after 1945, as both sides drew back from the brink and a "long peace" characterized the Cold War years, 1947–1991. There were, however, regional wars in Korea and Vietnam.