World War II

World War I (WWI) left Europe politically unstable. It was, in part, this instability that led to yet another international conflict, which would come to be known as World War II (WWII), in 1939. Also, in the years between 1918 and 1939, poverty rose in Europe and the United States. At the same time, governments grew weak, allowing Communism and Fascism to gain strength. Conflict soon erupted into almost every part of the world that year after German dictator and Nazi Party leader Adolf Hitler invaded Poland on Aug. 31 as part of a promise to avenge his country's defeat in WWI. In this conflict, the United States' allies included more than 50 nations, including Britain, China and the Soviet Union. Together, these nations were known as the Allied Powers. Fighting in opposition were the Axis Powers, which included Germany, Japan, Italy, Romania, Croatia, Hungary, Bulgaria and Slovakia. It is estimated that, in 1945, 45 to 60 million people had lost their lives during this worldwide conflict, including six million Jewish citizens who were murdered in detainment camps known as concentration camps.