The treaty was very humiliating to Germany, it was a dictate (they were forced to sign) as the British blockade remained in force and they had had to surrender masses of equipment to the allies. Not only there entire fleet but also 30,000 machine guns, 3000 trench mortars, 2000 aircraft and 5000 heavy artillery pieces. This would have made the war totally impossible to carry on.
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 demilitarised 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 Germanies armed forces was also key for several reasons
1. It was highly embarassing 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 militalistic 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 atract votes.
The harshness of Versallies also made many conservatives in Britain and...