America Enters the War

World War II was caused by the actions of two countries, Germany and Japan.  Germany’s invasion of Poland in September 1939 is considered the start of the Second World War.  During the first two years of the war, the United States remained neutral, even as Germany overran France and the majority of Europe, pounded Great Britain from the air during the Battle of Britain, and surprise attacked the Soviet Union.  Slowly, the isolationism of the United States eroded as America provided supplies to Great Britain and other allies via the Lend Lease Act.

Japan’s desire to dominate Asia militarily and economically led it to invade and brutalize Manchuria, China.  The United States refused to acknowledge these conquests, enacted an embargo on important resources, and began negotiations to reach a peace settlement with Japan.  During those negotiations, Japan attacked the American naval base at Pearl Harbor in Hawaii on December 7, 1941, killing thousands of Americans.  The next day, the United States declared war against Japan and officially entered World War II.