Americans like to think of World War II as a “great crusade,” but if it was, the country certainly didn’t seem all that fervent about rushing into it. Think of it: by the usual reckoning, World War II lasted six years, from the invasion of Poland on September 1, 1939, to Japan’s surrender on board the USS Missouri on September 2, 1945. US participation spanned less than four years of that total, a little over half the war. Of seven campaigning seasons, the United States missed the first three and was active only in the final four.

After the US strategic victories at the Battles of the Coral Sea (May 7–8, 1942) and Midway (June 4–7, 1942), the Japanese Imperial Navy was no longer capable of major offensive campaigns, which permitted the Allies to start their own offensive in the Pacific.

On December 7, 1941, Japan staged a surprise attack on Pearl Harbor, severely damaging the US Pacific Fleet. When Germany and Italy declared war on the United States days later, America found itself in a global war.

In 1945, US forces bounded forward in the central Pacific as combat reached ever bloodier crescendos.

In World War II, the three great Allied powers—Great Britain, the United States, and the Soviet Union—formed a Grand Alliance that was the key to victory. But the alliance partners did not share common political aims, and did not always agree on how the war should be fought.

When World War I ended in 1918, the American public was eager to reduce the country’s involvement in world affairs.

On December 7, 1941, Japan staged a surprise attack on Pearl Harbor, decimating the US Pacific Fleet. When Germany and Italy declared war on the United States days later, America found itself in a global war. 

One of Japan’s main goals during World War II was to remove the United States as a Pacific power in order to gain territory in east Asia and the southwest Pacific islands. Japan hoped to defeat the US Pacific Fleet and use Midway as a base to attack Pearl Harbor, securing dominance in the region and then forcing a negotiated peace. 
 

Adolf Hitler was appointed chancellor of Germany in 1933 following a series of electoral victories by the Nazi Party. He ruled absolutely until his death by suicide in April 1945. 

The Holocaust was Nazi Germany’s deliberate, organized, state-sponsored persecution and genocide of European Jews. During the war, the Nazi regime and their collaborators systematically murdered over six million Jewish people.