After WWI, the U.S. refused to join the League of Nations. Isolationism was exacerbated by the Depression. Americans were afraid their government would raise taxes and control industry. This national mood continued through the 1939 onset of WWII in Europe. However, German victories in France and Poland, and the Battle of Britain in 1940, began to change attitudes. After Pearl Harbor (12/07/41), a majority of the U.S. public favored going to war. Read more about World War II in A Brain. A Heart. The Nerve. (see NOVELS).