America insicura. L'internazionalismo realista di N. J. Spykman e la politica estera americana dalla Seconda guerra mondiale al "momento unipolare"

America's Strategy in World Politics and The Geography of the Peace make up the most comprehensive and systematic assessment pulished during the Second World War of the threats to the United States security posed by the expansionism of the Axis powers in Eurasia and, more in general, by the demise of the balance of power in what Spykman labaled the «rimland» of Eurasia. This article expounds briefly Spykman's case for a strategy of forward defense of the United States (as opposed to a strategy of hemispheric defense) and his call for a policy, after the war, of protracted political and strategic involvement of the United States in Europe and Asia. The article tries also to evaluate the influence of Spykman's geopolitical ideas on the american foreign policy during the Cold War and the «unipolar moment».