World War II (WWII) was a global war that lasted from 1939 to 1945 and involved most of the world's nations. It was the deadliest conflict in human history, with an estimated 70-85 million casualties, including civilians and military personnel. The war was fought between two opposing military alliances: the Allies, led by the United States, Soviet Union, United Kingdom, and China; and the Axis powers, led by Germany, Italy, and Japan. WWII resulted in significant social, political, and economic upheaval and had a lasting impact on the world.
