Cause of World War II.

World War I was immediately precipitated by the assassination of Archduke Francis Ferdinand of Austria-Hungary by a Serbian nationalist in 1914. There were, however, many factors that had led toward war. Prominent causes were the imperialistic, territorial, and economic rivalries that had been intensifying from the late 19th cent., particularly among Germany, France, Great Britain, Russia, and Austria-Hungary. Of equal importance was the rampant spirit of nationalism, especially unsettling in the empire of Austria-Hungary and perhaps …

…alliance systems in the Triple Alliance and Triple Entente and in a general armaments race. Nonetheless, a false optimism regarding peace prevailed almost until the onset of the war, an optimism stimulated by the long period during which major wars had been avoided, by the close dynastic ties and cultural intercourse in Europe, and by the advance of industrialization and economic prosperity. Many Europeans counted on the deterrent of war's destructiveness to preserve the peace.