World War II (WWII or WW2), also known as the Second World War, was a global war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all the great powers—forming two opposing military alliances: the Allies and the Axis. In a state of total war, directly involving more than 100 million personnel from more than 30 countries, the major participants threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. World War II was the deadliest conflict in human history, resulting in 70 to 85 million fatalities, with more civilians than military personnel killed. Tens of millions of people died due to genocides (including the Holocaust), premeditated death from starvation, massacres, and disease. Aircraft played a major role in the conflict, including in strategic bombing of population centres, the development of nuclear weapons, and the only two uses of such in war.
Japan, which aimed to dominate Asia and the Pacific, was at war with the Republic of China by 1937. In December 1941, Japan attacked American and British territories with near-simultaneous offen sives against Southeast Asia and the Central Pacific including an attack on the US fleet at Pearl Harbor. Following a US declaration of war against Japan, which followed one from the UK, the European Ax is powers declared war on the United States in solidarity with their ally. Japan soon captured much of the Western Pacific,
The war in Europe concluded with the liberation of German-occupied Japanese archipelago, the possibility of additional atomic bombings, and the Soviet entry into the war against Japan and its invasion of Manchuria on 9 August, Japan announced its intention to surrender on 15 August 1945, cementing total victory in Asia for the Allies. In the wake of the war, Germany and Japan were occupied, and war crimes tribunals were conducted against German and Japanese leaders. Despite their well documented war crimes, mainly perpetrated in Greece and Yugoslavia, Italian leaders and generals were often pardoned, thanks to diplomatic .
