The real and lasting victories are those ofpeace, and not of war.

— RalphWaldo Emerson

 World War II

World War II,or the Second World War, was a global military conflict lasting from 1939 to 1945 which involved most of the world’s nations, including allof the great powers,organised into two opposing military alliances: the Allies and the Axis.It was the most widespread war in history, with more than 100 million militarypersonnel mobilized. In a state of “total war”,the major participants placed their entire economic, industrial, and scientificcapabilities at the service of the war effort, erasing the distinction betweencivilian and military resources. Marked by significant action againstcivilians, including the Holocaust and the only use of nuclear weapons inwarfare, it was the deadliest conflict in human history, and it has been estimatedthat it resulted in fifty million to over seventy million fatalities.

The war isgenerally accepted to have begun on 1 September 1939, with the invasion of Poland by Nazi Germanyand subsequent declarations of war on Germany by France and most of the countries of the BritishEmpire and Commonwealth. Chinaand Japan were already at war by this date, whereas othercountries that were not initially involved joined the war later in response toevents such as the German invasion of the Soviet Union andthe Japanese attacks on the U.S. Pacific Fleet at Pearl Harbor and on British overseas colonies, which triggereddeclarations of war on Japan by the United States,the British Commonwealth, and the Netherlands.

The war endedwith the total victory of the Allies overGermanyandJapanin 1945. World War II left the political alignment and social structure of theworld significantly changed. While the UnitedNations was established to foster international cooperation andprevent future conflicts, the Soviet Unionand the United States emerged as rival superpowers,setting the stage for the Cold War, which lasted for the next forty-six years.Meanwhile, the acceptance of the principle of self-determination accelerated decolonizationmovements in Asia and Africa, while WesternEurope began moving toward economic recovery andincreased political integration.