Causes or origins of the conflict factors: First, the Second World War emerged in terms of confrontation between ideologies that were supported opposing political and economic systems. Unlike the previous war, marked by a single system predominantly capitalist liberalism, common to both sides "in the Second World War there were three opposing ideologies: liberalism, democracy, Nazism and fascism and Soviet communism. The latter two systems, despite being contrary to each other, had in common a strong state organization and the totalitarian personality cult of a charismatic leader, the opposite characteristics of liberalism that posits democracy as a form of government and freedom and equality of individuals as a form of society.
Second were the ethnic problems that present for centuries, became more serious when the changes take effect border created by the Treaty of Versailles, which adversely affected mainly Germany and Austria-countries populated by Germans, and reduced considerably its territories. This fact was crucial to disseminate these changes can the feeling of superiority of the Germanic race-identified by Adolf Hitler as "Aryan race" according to an idea developed in the nineteenth century German philosophy-against racial groups, mainly Jews who controlled the capitalist economy, and who, from the perspective of the Nazis, had divided the Germanic people and disrupted economic development.
Moreover, Hitler's insistence to avoid compliance with the Treaty of Versailles caused different reactions among the victorious countries: France, which feared a new attack from Germany, wanted to avoid at all costs resurgent military power from the neighboring nation. In contrast, the British government and the United States underestimated the danger posed to German rearmament collective security, considered the Treaty of Versailles had been too unfair, and were sympathetic to the anti-trend adopted by Nazi Germany because it could be a barrier capable of stopping Soviet expansionism into Europe, described then by the Western democracies as a threat more and more serious than Nazism itself. Because of this fear of communism, the British government adopted a policy of "appeasement" for German expansionism under the idea that by making concessions to Hitler could prevent a new war and would further its cooperation against the Soviet threat .
Third, in the decade of the thirties, the world situation was very different from 1914. Apart from the disruption caused by the economic crisis that began in the United States still remained the devastating effects of the First World War, which had been a huge transformation in all spheres of human life and led to major crises in virtually all countries Earth. In addition, the sequel to international tensions that produced conflict, paving the way for a new war, despite attempts by the League of Nations to prevent it. For this reason, we can say that World War II originated directly from the first, hence the two conflicts, linked by the interwar period, constitute what is regarded as the "Second Thirty Years War" in modern history of humanity.
Like the World War II comes in two phases:
a) from 1939 to 1941 when it takes place mainly in Europe and shows a direction favorable to the Axis powers;
b) from 1942 to 1945, when the war takes on global dimensions and gradually becomes favorable to the Allies led by Britain, U.S. and USSR.
