World War II began in 1939 as a conflict between Germany and the combined forces of France and Great Britain and eventually included most of the nations of the world before it ended in August 1945. It caused the greatest loss of life and material destruction of any war in history, killing 25 million military personnel and 30 million civilians. By the end of the war, the United States had become the most powerful nation in the world, the possessor and user of atomic weapons. The war also increased the power of the Soviet Union, which gained control of Eastern Europe and part of Germany.
World War II was caused in large part by the rise of totalitarian regimes in Germany and Italy and by the domination of the military in Japan. In Germany, ADOLF HITLER, head of the National Socialist or Nazi party, became chancellor in 1933. Within a short time, he had assumed dictatorial rule. Hitler broke the Versailles Treaty, which had ended WORLD WAR I and disarmed Germany, and proceeded with a massive buildup of the German armed forces. Hitler believed that the German people were a master race that needed more territory. His first aim was to reunite all Germans living under foreign governments. In 1936 he reclaimed the Rhineland from French control and in 1938 annexed Austria to Germany. That same year he took over the German areas of Czechoslovakia and in 1939 annexed all of that country.
Though France and Great Britain had acquiesced to Germany's actions, they soon realized that Hitler had greater ambitions. When Germany invaded Poland on September 1, 1939, Great Britain and France declared war on Germany. With the invasion of Poland, World War II began. Poland was quickly defeated, and for a period of time a "phony war" ensued, with neither side making any military moves. This situation changed in the spring of 1940, when Germany invaded Holland, Belgium, and France. Again, German military forces overwhelmed their opponents, leaving Great Britain the only outpost against Germany.
During the 1930s the United States government had avoided involvement in European affairs. This traditional policy of "isolationism" became more problematic after the war began in 1939. President FRANKLIN D. ROOSEVELT moved away from an isolationist foreign policy and sought to assist Great Britain and France, while keeping the United States a neutral party to the conflict. This strategy led to the repeal of the arms embargo in the Neutrality Act of 1939 (22 U.S.C.A. § 441), allowing the sale of military equipment to Great Britain...