The article contains well structured material on the school of classical political realism and on directions that descend from it: theories of neorealism, varieties of geopolitics and of geoeconomics. The classical realists demonstrated in their time that divergence of interests, the leading powers’ urge toward the expansion of their influence in the world endanger stability, cause conflicts, including armed conflicts, between subjects of the world politics. With its evolution, the realist school (in its structuralist variant) came to the comprehension of the significance of systemic mechanisms of securing order, to the understanding that states are not in a condition to defend their interests individually.