The term geopolitics (Geopolitik in German) was developed by Rudolf Kjéllen, a Swedish political scientist in 1905. As a subbranch of political geography, geopolitics focused on the spatial development and needs of the State. It combined Friedrich Ratzel's theory on the organic nature of the State along with Sir Halford J. Mackinder's Heartland Theory to justify expansionistic practices of countries.
In the 1920s, German geographer Karl Haushofer used Geopolitik to support German expansion. Haushofer felt that densely populated countries like Germany should be allowed and entitled to expand and acquire the territory of less populated countries (such as Czechoslovakia and Poland.) This concept, known as Lebensraum (living space) was actually developed by Ratzel, who is often called the founder of political geography. Haushofer twisted Ratzel's theories to develop the pseudo-science of Geopolitik. Haushofer's Lebensraum permitted the expulsion of "lesser" peoples to further the goals of the growing State.
Haushofer founded and edited the journal Zeitschrift für Geopolitik in 1924 and then became a professor of geopolitics once the Nazis came to power in Germany in 1933. The journal, and Haushofer's career, only lasted until 1944.
While Haushofer was an acquaintance of Rudolf Hess, Hitler's deputy, his ideas were only of limited influence on Hitler. For Hitler had his own concept of geography and the expansion of the state. In his autobiography Mein Kampf, Hitler explained that Germany had the "moral right to acquire [the] foreign land and soil" of "lesser" races. Haushofer primarily provided the academic and scientific support for the expansion of the Third Reich.
Outside of Germany, only the Japanese geographical community supported the work of Haushofer and the ideas of geopolitics as a weapon of conquest.
Haushofer's son Albrecht was indicted in the July 20, 1944 plot to assassinate Hitler so the elder Haushofer was imprisoned in a concentration camp. Following the war, Haushofer was interrogated by the allies and in 1946, distraught over the death of this son, Haushofer committed suicide.
Thus, a dark period in the history of geography came to a close.