Geopolitics deals with the use of existing geographic advantages with a view to strengthening power-political positions. This also comprises foreign affairs, diplomacy, economy, land, naval and air power, the search for allies, the use of allies, and in the case of the USA, also the fixing of the national interest. Referring to the USA, terms such as American Century, Pax Americana, American Primacy, American Empire, United States Dominance, Hegemonial Politics, Unilateralist Empire or Global Strategy are unthinkable without the „blessings of geography“ and without geopolitical foundations. Additionally, with the USAone can understand „geo-conceptions“ more easily than with other powers, because here there exists more transparency in the discussions about goals and intentions and because political and strategic realization is as perceptible as any non-realization. At the end of the 20th century American geopolitics started to move, and it is still not clear how long the instabilities, which have occurred all over the world, will last, but time and again the USA have gone through crises they have emerged stronger than before. Geopolitics always is macro-politics related to geography. Thus, it becomes obvious that small states cannot have geopolitics. On the contrary, they are part of the geopolitics of great powers, their politics and their strategies mostly depending on the goodwill of others. As far as political science and international relations are concerned, within the framework of the classification with Realist Politics (Realism, Realist School) and Idealist Politics (Idealism, Idealist School, Liberalist School) and all their possible fusions, which was developed after 1945, geopolitics and its sub-geo fields are to be classed with the Realist field; only the World Models and One World Government ideas are utopian and therefore close to the Idealist School. For this reason John J. Mearsheimer has detected a contrast between Liberalism and Realism, and he considers this separation into these antagonistic fields to have started between the two World Wars, although he doubts the basic idea of such strict classifications. On the other hand, Michael C. Desch supports this classification and demonstrates it with the foreign policy of the USA which varies from one school to the other and back. One often overlooks that the pre-colonial America showed Christian-fundamentalist features which led to social and political divergence. Although the intolerant Puritans were rebellious against the crown, they considered America as an advanced part of England, and certainly not „paradise“. In historical retrospect, however, it was assigned a transfigured „higher mission“. From a geostrategic-historical point of view, one can divide the development of American strategies into the phase of defence of the western hemisphere and of the continental glacis, into the oceanic era of the 20th century, and into the trans-oceanic (or global) era after 1944/45, the latter being marked by American presence on all oceans and by military bases all over the world. It is de facto an extension of the Monroe Doctrine to great parts of the world and marks the victory of the USA as a naval power over the Eurasian land powers.