No sooner had “the war to end all wars” ended, when the next catastrophe followed. The major causes of World War II were numerous. They include the impact of the Treaty of Versailles following WWI, the worldwide economic depression, failure of appeasement, the rise of militarism in Germany and Japan, and the failure of the League of Nations. In 1936, Hitler made alliances with Italy and Japan, the Axis Powers.  On September 1, 1939, German troops invaded Poland. Britain and France immediately declared war on Germany. World War II had begun in Europe. Meanwhile in the East, Japan needing natural resources for its factories invaded China and Korea in 1931. Ignoring the League of Nations Japan continued to occupy China and Korea and invaded other areas of South East Asia including Vietnam. Japan felt that its expansion could be threatened by the United States and attacked Pearl Harbor, Hawaii, in December 1941. World War II had begun in Asia. World War II ended with the unconditional surrender of Germany in May 8 (to the Allies) & 9 (to Russia), 1945. In the East, the war ended when Japan surrendered unconditionally on Aug. 14, 1945, signing their surrender on Sept. 2. The Japanese surrender occurred after the United States dropped atomic bombs on Hiroshima and Nagasaki on Aug. 6 and 9, respectively.