World War II was not caused by one person, but by the unbalanced economic development of capitalist countries. Germany doesn't have enough raw materials and markets, industry can't play a sufficient role, and agriculture can't feed the whole country. Therefore, they need to calm internal contradictions through high-pressure policies at home and actively expand abroad to alleviate the social decline brought about by economic depression. When the whole country wants to go to war with foreign countries, it makes no difference whether there is Hitler or not.