Karl Haushofer (1869-1946), a German general and later academic, popularized the concept of geopolitics. Although not a member of the Nazi Party, was one of its intellectual sources. Rudolf Hess, one of his students, would soon introduce him to Adolf Hitler, and the biological theory certainly affected Hitler's writings on Lebensraum in Mein Kampf, and possibly the Nazi race and biological ideology in general. 
Early and military life
He joined the Imperial German Army in 1887. In 1896, he married Martha Mayer Doss, the daughter of a Jewish merchant from Mannheim. In 1908 he was sent to Tokyo to study and learn Japanese. He was much influenced by the ideas of Aritomo Yamagata, founder of the Imperial Japanese Army. He observed, in his book Dai Nipon, that not all of Japan was a warrior nation, and that the key leadership came principally from the Satsuma and Chosu Clans, much as Germany had a traditional military elite. Based in part on his Japanese studies, received a degree in Geography, Geology and History from the University of Munich in 1913.
During the First World War he served on the Eastern Front in Russia and the Western Front in France.
Haushofer and Germany
Haushofer retired from the German Army as a major general, and began teaching at the University of Munich in 1919. His essential core theory was that the state "is a biological organism which grows or contracts, and that in the struggle for space the strong countries take land from the weak." Influencing his thinking were the works of Oswald Spengler, Alexander Humboldt, Carl Ritter, Friedrich Ratzel, and Halford Mackinder. 
Relationship with Nazis
It is not questioned that Rudolf Hess was among his students, and introduced him to Hitler. Haushofer visited Hitler in Landsberg Prison after the Beer Hall Putsch, and gave him a copy of Ratzel's Political Geography, but claims that Haushofer was a major guide to Mein Kampf are probably much exaggerated. Haushofer did speak before Nazi meetings in the mid-twenties. He did form the German Academy, eventually taken over by the Reich Ministry of Propaganda and Public Enlightenment, and help direct it in a Nazi direction. 
Hess, in England after his 1941 flight, mentioned the ideas of Haushofer about uniting the great Nordic countries. 
In postwar interrogations by Father Edmund Walsh, he suggested that geopolitics was legitimate until 1933, but he supported Nazi foreign policy until 1938. He told Walsh that the syllabus at the Georgetown University School of Foreign Service, which Walsh showed him, was quite similar to that of Haushofer's Institute. Walsh, drawing at least to some extent on Haushofer, became a leading American anti-Communist.
Haushofer and his wife committed suicide shortly after the end of the Third Reich. His son, Albrecht Haushofer, was executed for complicity in the 1944 assassination attempt against Hitler on 22 April.
- Holger H. Herwig, The Daemon of Geopolitics: Karl Haushofer, and Adolf Hitler
- Dylan Kirk (2001), After Battle, Tighten Your Helmet Strings: The Development of the Imperial Japanese Navy, 1875-1 905, Master's thesis, University of Calgary, p. 10
- Karl Haushofer, Spartacus
- Gearoid O Tuathail (2000), Critical Geopolitics, CRC Press, pp. 35-37
- William Shirer (1960), The Rise and Fall of the Third Reich, Simon & Schuster, p. 837
- O Tuathail, pp. 37-38
- Shirer, p. 1073