Let's say Adolf Hitler dies early on in the war, in 1914.
Do the Nazis still exist? Is there still a WW2?
Do the Nazis still exist? Is there still a WW2?
This is essentially one of the bigger questions in History - do actions result from the activities of "Great People" or are they the response to wider forces. I think that wider forces shape the world, but different people would use them in a different way, creating differences to the world.
In this case one could see four major elements - ethnic-racist nationalism; demands for territorial revisionism; acute class conflict (especially with the success of the Bolshevik Revolution); and a protracted crisis of capitalism. These were present throughout Europe, but found their greatest expression in Germany thanks in many ways to the shock of loosing the First World War and the results of the Treaty of Versailles. These forces pushed numerous people into the Nazi camp, giving them the chance to force their way into government, and this may well also have happened with another leader. Whether such a leader would play so much on the first of these forces and so drive a genocidal campaign may be unlikely - but maybe they would focus more on the class element, driving a war against the workers states, or territory driving war to recapture the lands once owned.