In March 1936, Germany reoccupied the Rhineland (which had been taken away from them after World War I). In March 1938, they annexed Austria and by October occupied the Sudetenland. Despite these violations, the rest of Europe did nothing.

Hitler viewed Europe’s lack of response as an open invitation to continue taking territories.  On September 1, 1939, Germany invaded Poland in a blitzkrieg attack, conquering the nation in only a month. However, as a result, Great Britain and France immediately declared war on Germany and World War II was on.