At the start of December, 1941, much of the world was at war. Under the
leadership of Adolf Hitler, Germany occupied many countries in Europe. Japan had
signed a pact with Germany and Italy and had attacked many of its neighbors. The
United States sent supplies to Great Britain to help with the war effort but hadn't yet
joined the war. Many citizens of the United States did not like the idea of the country
joining the war. This changed on December 7, 1941.
In the early morning hours of December 7, the Japanese sailed a fleet of ships
within a few hundred miles of Pearl Harbor. Pearl Harbor is a naval base in Hawaii.
Over 300 airplanes were launched from the Japanese aircraft carriers to attack
American Navy ships at the naval base. The sneak attack caught many people
unprepared. Around 20 ships and over 300 planes were either damaged or
completely destroyed. There were also many casualties. The next day, President
Franklin D. Roosevelt declared war on Japan.
What is a central idea of the passage?