Political geography is concerned with the study of both the spatially uneven outcomes of political processes and the ways in which political processes are themselves affected by spatial structures. Conventionally, for the purposes of analysis, political geography adopts a three-scale structure with the study of the state at the centre, the study of international relations (or geopolitics) above it, and the study of localities below it. The primary concerns of the subdiscipline can be summarized as the inter-relationships between people, state, and territory. History The origins of political geography lie in the origins of human geography itself, and the early practitioners were concerned mainly with the military and political consequences of the relationships between physical geography, state territories, and state power. In particular there was a close association with both regional geography, with its focus on the unique characteristics of regions, and environmental determinism, with its emphasis on the influence of the physical environment on human activities. This association found expression in the work of the German geographer Friedrich Ratzel, who in 1897 in his book Politische Geographie, developed the concept of Lebensraum (living space) which explicitly linked the cultural growth of a nation with territorial expansion, and which was later used to provide academic legitimisation for the imperialist expansion of the German Third Reich in the 1930s. The British geographer Halford Mackinder was also heavily influenced by environmental determinism and in developing his concept of the 'geographical pivot of history' or the Heartland Theory (in 1904) he argued that the era of sea power was coming to an end and that land based powers were in the ascendant, and, in particular, that whoever controlled the heartland of 'Euro-Asia' would control the world. This theory involved concepts diametrically opposed to the ideas of Alfred Thayer Mahan about the significance of sea power in world conflict. The heartland theory hypothesized the possibility of a huge empire being created which didn't need to use coastal or transoceanic transport to supply its military–industrial complex, and that this empire could not be defeated by the rest of the world allied against it. This perspective proved influential throughout the period of the Cold War, underpinning military thinking about the creation of buffer states between East and West in central Europe. The heartland theory depicted a world divided into a Heartland (Eastern Europe/Western Russia); World Island (Eurasia and Africa); Peripheral Islands (British Isles, Japan, Indonesia and