    among the main long-term causes of world war ii were the rise of italian fascism in the 1920s, japanese militarism and invasions of china in the 1930s, and especially the takeover in 1933 of germany by the nazi party. trouble arose in weimar germany that experienced strong currents of revanchism after the treaty of versailles that concluded its defeat in world war i in 1918. dissatisfactions of treaty provisions included the demilitarizarion of the rhineland, the prohibition of unification with austria and the loss of german-speaking territories such as danzig, eupen-malmedy and upper silesia despite wilson's fourteen points, the limitations on the reichswehr making it a token military force, the war-guilt clause, and last but not least the heavy tribute that germany had to pay in the form of war reparations, and that become an unbearable burden after the great depression. after his rise and take-over of power in 1933 to a large part based on these grievances, adolf hitler and the nazis heavily promoted them and also ideas of vastly ambitious additional demands based on nazi ideology such as uniting all germans (and further all germanic peoples) in europe in a single nation; the acquisition of "living space" (lebensraum) for primarily agrarian settlers (blut und boden), creating a "pull towards the east" (drang nach osten) where such territories were to be found and colonized, in a model that the nazis explicitly derived from the american manifest destiny in the far west and its clearing of native inhabitants; the elimination of bolshevism; and the hegemony of an "aryan"/"nordic" so-called master race over the "sub-humans" (untermenschen) of inferior races, chief among them slavs and jews. tensions created by those ideologies and the dissatisfactions of those powers with the interwar international order steadily increased. italy laid claim on ethiopia and conquered it in 1935, japan created a puppet state in manchuria in 1931 
Causes_of_war Chronology_of_World_War_II Interwar_period Politics_of_World_War_II