Most historians would argue that the Treaty of Versailles was a rather efficient cause of World War II. Among its more egregious provisions was the "war guilt clause" which shouldered Germany with complete and total responsibility for the war. Additionally, Germany was compelled to pay reparations which were eight times greater than the entire country's net worth. Of course the reparations were not paid in full; however this caused tremendous resentment on the part of the German people, and proved fertile ground for the likes of Adolf Hitler to focus that resentment. The Treaty gave territory to France which was German in culture and language, which was also an untenable situation.
Additionally, Japan had come into World War I expecting to gain territory in Asia, primarily German territories. By the terms of the Treaty, Japan walked away empty handed. There is some argument that there was a racial element at work here, as Woodrow Wilson was quite racist. He had Ho Chi Minh thrown out of the Conference when he asked for self-determination of the people of Indochina.
Most of the mistakes made at the Treaty negotiations were because France and England were determined to cripple Germany; and Woodrow Wilson, who should have been more forceful, made broad concessions to assure the Treaty would include his dream of a League of Nations. The end result was too high a price for an organization that soon failed. Had Wilson been more forceful, perhaps World War II could have been avoided, although that is a subject of substantial conjecture.
After WWII Germany was devastated:
1)it lost all its colonies
2)gave back to the French the areas of Alsace and Lorraine. These two are quite significant since the were won by the Germans during the Franco-German war.
4) very heavy economic compensations and not to mention the loss of the german youth
All these conspired to rob the german people of their common sense, and in their moment of weekness (later during the economic chrisis) they turned into a man they didn't fully understand. Hitler.
In the elections of 1928, Hitler received only 2,6% of the total votes. After the economic chrisis, during the election of 1933, he received a total of 44%!
The numbers talk by themselves, and they show that the German people were not satisfied at all with the Treaty of Versailles and of course the followng events.