Officially, World War II began when Nazi Germany invaded Poland in September 1939 and the French and English declared war against Germany as a result of that invasion. But the war's beginnings came long before this invasion. World War II was the product of a lot of things coming together in just the wrong way at just the wrong time.
The World War I peace agreement
When the Great War ended, the winners (Britain, France, the United States, and Italy) wanted the losers (Germany, the Austro-Hungarian Empire, and the Ottoman Empire) to pay. Because the Austro-Hungarian and Ottoman Empires no longer existed, that left Germany to bear the brunt of the victors' vindictive peace agreement. Humiliated and broke, Germany began nursing a big-time grudge. The victors themselves weren't even happy with the outcome. Some (Italy) felt cheated; some (France) felt that Germany hadn't been punished enough, and some (the U.S.) just wanted the heck out of Dodge.
In addition, the peace agreement created new nations (Poland, Czechoslovakia, and Yugoslavia) in Eastern Europe from the wrecked Austro-Hungarian Empire and other pieces of land from here (Germany) and there (the Soviet Union). Think that didn't tick everybody off?
The global economy
All the nations experienced financial troubles following World War I. The European nations (especially Germany, with the war debt hanging over its head) were practically destitute. Slowly, each made an economic recovery — just in time for the world economy to spiral downward. The U.S. stock market crashed in 1929, and the economies in Europe tanked pretty soon after that. Weakened by the war, no European nation was able to stop the economic downturn. And many saw the ruined economy as an indication that capitalism and democracy had failed.
The rise of totalitarianism
With the world in such a mess, folks looked toward their governments to solve their problems, and those countries without a strong tradition of democratic rule were susceptible to promises made by future tyrants who claimed that by consolidating power in one party and one man, they could provide stability and order.
As a result, in Germany specifically (and in Italy earlier), the fledgling democracies gave way to dictatorships and eventual totalitarian rule (that is, all aspects of life are controlled by the dictator). In Italy, this dictator was Benito Mussolini; in Germany, it was Adolf Hitler.
The birth of Fascism and Nazism
Fascism is a political ideology in which the state is exalted above all else. All effort and resources are committed to glorifying the state. Individual freedom doesn't exist; there is only the freedom to serve the state. Fascists believe that people reach their potential only through service to their nation. If the nation is great, the people are great. And the best representation of the nation's greatness is through war. Italy was Fascist, as was Spain after the Spanish Civil War.
Nazism is Fascism with a significant difference: the race issue. The Nazis believed that race is the fundamental trait and therefore the defining characteristic of a people. Just as dogs are genetically predisposed to certain roles (some hunt and others herd, for example), each race is genetically predisposed to certain roles. Some are leaders; other races (the "inferior" ones) are meant to be mastered. The Aryan race is, according to Nazis, the Master Race. Then, in descending order are, non-Aryan Caucasians, Asians, Africans, and finally Jews. The Jewish people occupied a special place at the bottom of the Nazi racial hierarchy for the following reasons:
- They "corrupted" the other inferior races and the weak minded of the Master Race with what Hitler thought of as Jewish ideas: equality among people and individual freedom.
- They wanted to take over the world and thus posed a specific threat to the Master Race who, as the Master Race, deserved to rule the world.
- They were "parasites" who betrayed Germany during World War I.
The rise of Hitler
There have always been tyrants and people who abused power, and in many ways, Hitler was no different than any other dictator. He consolidated power by eliminating anyone who could oppose him. He targeted and abused groups he didn't like. He used propaganda as a tool to lull the German people into believing that what he told them was true.
In other ways, Hitler was different. He had the power of an industrialized nation behind him. He had the capability to export his policies all over Europe through diplomatic trickery and lies and then through war. He had the certainty of his fanatical vision of a Jew-free Europe. And, maybe most frightening of all, he had the ability to make the German people as a whole believe that, by following him down the path to hell, they were fulfilling their destiny for greatness.
The British and French fear of another war
The British and French, having just been through one horrific world war (although they didn't call it that at the time), were willing to do just about anything to make sure that they didn't find themselves in another horrific war. For both countries, this determination to avoid conflict resulted in their policy of appeasement. By giving in to the demands of aggressors, such as Hitler, they hoped to avert another crisis that would lead to war. Obviously, this strategy didn't work.
The isolationism of the United States
The United States, separated from Europe by an ocean, wanted to remain separated from Europe. Like the French and British, the Americans had seen enough of war. They learned as much about European politics and intrigue and blood feuds as they wanted to during the Great War, and they had no intention now of allowing themselves to get mixed up in that mess again. So they developed an isolationist policy and naively insisted that what went on in Europe — or anywhere else in the world, for that matter — was not their concern.
The empire building of Japan
Japan, long a key player in Asia, wanted to consolidate its power there. Japan still held the German bases that it had occupied in China during World War I, and as one of the victors, Japan got to keep large sections of Chinese territory that had once been controlled by the Germans, in addition to being given control of islands that had belonged to Germany. Japan also sought to increase its holdings in China, which, in addition to being a problem for the Chinese, was also a problem for the United States, who had interests there, too.