After World War I, the world looked for a common enemy; in the end, Germany was the prime target. The Treaty of Versailles directly targeted the country, with Article 231, the "war-guilt clause", forcing Germany to accept any and all punishments deemed fair by the League of Nations.
Many Germans took personal offense to this, and began to look for someone to blame for their newfound economic troubles. One of these people was Adolph Hitler, of whom formed the Nazi Party and caused the creation of many offshoot organizations, which began the climb to igniting a barrier of hate.