To what extent did the specific Weltanschauung of American elites precisely weigh on the decision-making process behind the strategy of anticommunist containment? Among many possible structural influences, the Cold War historiography partly includes theoretical contributions of “geopoliticians,” especially those of Halford Mackinder and Nicholas J. Spykman. Nevertheless, the philosophy of the latter, to whom absolutely no biography has ever been devoted, proves more paradoxical than expected. Based on original research on the course of Spykman’s career, this paper proposes a reassessment of the causal relationships between classical geopolitical thinking and the containment strategy practiced by the United States since 1947.