World War II: A Global Conflict

World War II, spanning from 1939 to 1945, was a global conflict that involved the majority of the world's nations, including all great powers, which formed two opposing military alliances: the Allies and the Axis. The war was precipitated by the unresolved issues from World War I, economic instability during the Great Depression, and the rise of totalitarian regimes in Germany, Italy, and Japan. Key events included the Holocaust, the use of atomic bombs on Hiroshima and Nagasaki, and the establishment of the United Nations post-war to foster international cooperation and prevent future conflicts. The war fundamentally reshaped international relations and led to the emergence of the United States and the Soviet Union as superpowers.