WWII: Why did the U.S. get involved in the war?

At the beginning, the United States expressed the determination to
remain a neutral nation. When W.W.II began, opinions among the Americans were
divided. Some felt that the Nazi Germany was not only a threat to Europe and
democracy, but to civilization itself. Other believed that Europe's wars were
no affairs of the U.S.
As the war progressed, the U.S. found itself getting involved. They
felt sympathy for the British after what happened at Dunkirk. They started
helping G.B. with weapons and food. 50 old American naval destroyers were sent
to Britain. Now it was clear the U.S. were on the Allies side but they still
weren't physically involved in the big war.
On December 7, 1941, the Japanese launched a surprise attack on the
American naval base at Pearl Harbor, Hawaii. Their aim was to strike such a
severe blow that the U.S. would not rival the Japanese in the Pacific(boy were
they wrong or what). American ships were sunk or badly damaged. American dead
totaled over 2,300. The United States weren't going to take that from the
Japanese and on December 8, 1941, congress declared war on Japan and so did the
British Parliament. Three days later, Germany and Italy declared war on the
U.S., and the congress replied with its own declaration of war. At this time,
the United States of America were full-fledged belligerent in World War II.