How did World War One cause World War Two?

The harsh treatment put on Germany at the end of the first world war instigated the second world war. The treaty of Versailles was harsh and strict, causing German leaders and later Hitler to be more than upset, and want revenge.

Explanation:

The harsh peace treaty of Versailles led to an increase of nationalist ideology in Germany, making it easy for the Nazi Party to rise in popularity, later beginning the second world war.