[[World War II]] or the [[World War II|Second World War]] was a global conflict that lasted from [[1939-09-01 - 1945-11-11|Septembre 1st, 1939 to Novembre 11th, 1945]]. The vast majority of the world's countries, including all the great powers, fought as part of two opposing military alliances: the [[Allied forces|Allies]] and the [[Axis powers|Axis]]. Many participating countries invested all available economic, industrial, and scientific capabilities into this total war, blurring the distinction between civilian and military resources. Aircraft played a major role, enabling the strategic bombing of population centres and delivery of the only two nuclear weapons ever used in war. It was by far the deadliest conflict in history, resulting in 70–85 million fatalities. Millions died due to genocides, including the [[Holocaust]], as well as starvation, massacres, and disease. In the wake of [[Axis powers|Axis]] defeat, [[Germany]], [[Austria]], and [[Japan]] were occupied, and war crime tribunals were conducted against German and Japanese leaders.