the spread of his geopolitical ideas, magazine articles and books. By 1924, as the leader of the German geopolitik school of thought, Haushofer would establish the Zeitschrift für Geopolitik monthly, devoted to geopolitik. His ideas would reach a wider audience with the publication of Volk ohne Raum by Hans Grimm in 1926, popularizing his concept of lebensraum. Haushofer exercised influence both through his academic teachings, urging his students to think in terms of continents and emphasizing motion in international politics, and through his political activities. While Hitler's speeches would attract the masses, Haushofer's works served to bring the remaining intellectuals into the fold. Geopolitik was in essence a consolidation and codification of older ideas, given a scientific gloss: Lebensraum was a revised colonial imperialism; Autarky a new expression of tariff protectionism; Strategic control of key geographic territories exhibiting the same thought behind earlier designs on the Suez and Panama canals; and Pan-regions based upon the British Empire, and America's Monroe Doctrine, Pan-American Union and hemispheric defense. The key reorientation in each dyad is that the focus is on land-based empire rather than naval imperialism. Ostensibly based upon the geopolitical theory of US naval officer Alfred Thayer Mahan, and British geographer Halford J. Mackinder, German geopolitik adds older German ideas. Enunciated most forcefully by Friedrich Ratzel and his Swedish student Rudolf Kjellén, they include an organic or anthropomorphized conception of the state, and the need for self-sufficiency through the top-down organisation of society. The root of uniquely German geopolitik rests in the writings of Karl Ritter who first developed the organic conception of the state that would later be elaborated upon by Ratzel and accepted by Hausfhofer. He justified Lebensraum, even at the cost of other nations' existence, because conquest was a biological necessity for a state's growth. Friedrich Ratzel Ratzel's writings coincided with the growth of German industrialism after the Franco-Prussian war and the subsequent search for markets that brought it into competition with England. His writings served as welcome justification for imperial expansion. Influenced by Mahan, Ratzel wrote of aspirations for German naval reach, agreeing that sea power was self-sustaining, as the profit from trade would pay for the merchant marine, unlike land power. Haushofer was exposed to Ratzel, who was friends with Haushofer's father, a teacher of economic geography, and would integrate Ratzel's ideas on the division between sea and land powers into his theories by saying that