Irredentism is a term used to describe a situation in which a minority group in one country shares the culture and heritage of another country. The minority group may attempt to have their region annexed into the mother country or may be happy in the country they are in. Adolf Hitler used irredentism as an excuse to invade and conquer Czechoslovakia in 1938. He claimed that the Germans in the Sudetenland, a part of Czechoslovakia, were being treated unfairly and thus this area should be annexed to Germany. Though Germany’s annexation of Czechoslovakia did not start World War II, it was the Nazis’ first direct aggressive step toward conquering Europe.