World War II involved the the vast majority of nations of the world that were eventually formed into two opposing military alliances: the Allied Powers and the Axis Powers. This conflict directly involved more than 100 million people from more than 30 different countries. Nations entrenched in this conflict committed their entire economic, industrial, and scientific capabilities. Countries that may have been seen as having different ideologies fought together against a common enemy. The Second World War resulted in the defeat of the world's most notorious tyrant, but also extended the Soviet Union's power structure and enabled a communist movement to achieve power in China. The end of this war marked a shift in power away from western Europe and toward the United States and Soviet Union.