How did the Treaty of Versailles help cause World War 2?

The allies instead of providing a peace settlement based on the 14 point plan as Germany had though instead made the treaty very humiliating with the aim of keeping the Germans down.

The key points of the treaty that contributed to the conditions in Germany that lead to the rise of National Socialism are;

1. The war guilt clause
2. £6,600mil to be paid in reparations
3. Disarmament, The Rhineland was demilitarized the size of the army was limited, the navy was only allowed a handful of pre dreadnoughts and minor ships, as well as no air force and no submarines
4. Anschluss was forbidden and 14% of its land lost as well as all of Germany's colonies.

The war guilt clause angered many Germans and fueled the fires of the "stab in the back" conspiracy's theory.

Reparations made Germany poor, because of this many tended towards far right or far left parties. Failure to pay resulted in the french invasion of the Rhur region in 1923 further increasing hate for the treaty and the french.

The reduction of Germany's armed forces was also key for several reasons

1. It was highly embarrassing especially to a country that had years earlier been the greatest land power in the world. And to a very militaristic/ nationalistic country.

2. The weakening of the army meant that it was unable to control the militaristic wings of the Nazi and Communist parties forcing Papen to cut a deal with Hitler.

Hitler used the pretext of reuniting Germany to get back land and to attract votes.

The harshness of Versailles also made many conservatives in Britain and France feel sorry for Germany combined with war weariness and the fear of communism lead to the policy of appeasement.
It was too hard on Germany in requiring money to be paid by Germany to the allies.