In the lead-up to (1938) and the invasion of Poland (1939) the propaganda of Nazi Party in Germany used popular feelings of wounded national identity aroused in the aftermath of the First World War to promote policies of . Studies of the homeland focused on the lost colonies after the establishment of the Second Polish Republic which was ratified by the Treaty of Versailles (), as well as the "eternal Jewish threat" (, 1937). Emphasis was put on the need for rearmament and the pseudoscience of superior races in the pursuit of "blood and soil".