National Socialism, or Nazism, was a German political movement founded in Munich, Germany, about 1920. Its full title was the National Socialist German Workers' Party (Nazi, for short). Adolf Hitler led it from 1921 to 1945, a violent German nationalist who fed on the emptiness many Germans felt after World War I (1914-18). They had lost the war, and they believed that the harsh demands other nations made on them in the Treaty of Versailles (1919) were unfair. Hitler claimed that the German Army had never been beaten. Instead, Germany had lost because the German politicians who came to power at the end of the war in November 1918 had betrayed it. Hitler demanded that they should be booted from office. He wanted their power handed over to those who would free Germany from the Versailles Treaty and restore it to greatness.

One side of National Socialism was its appeal to German nationalism...