World War II was a global war that lasted from 1939 to 1945 involving the majority of the world's countries - including all of the great powers - forming two opposing military alliances. The major participants threw their entire economic, industrial, and scientific capabilities into the war effort. It was by far the deadliest conflict in human history, resulting in 70 to 85 million fatalities, due to actual battles as well as genocides (The Holocaust), starvation, massacres, and disease. In the wake of defeat, Germany and Japan were occupied, and war crimes tribunals were conducted against German and Japanese leaders.
