The fundamental underlying cause of the Cold War was the reinforcing belief in both the Soviet Union and the United States that confrontation was unavoidable, imposed by history. Soviet leaders believed that communism would ultimately triumph in the world and that the Soviet Union was the vanguard Socialist/Communist state. They also believed that the Western “imperialist” powers were historically bound to pursue a hostile course against them. For their part, American and other Western leaders assumed that the Soviet Union was determined to enhance its own power and to pursue expansionist policies by all expedient means in order to achieve a Soviet-led Communist world. Each side thought that it was compelled by the very existence of the other side to engage in a zero-sum competition, and each saw the unfolding history of the Cold War as confirming its views.

The prevailing Western view was wrong in attributing a master plan to the Kremlin, in believing that Communist ideology impelled Soviet leaders to advance, in exaggerating Communist abilities to subvert the Free World, and in thinking that Soviet officials viewed military power as an ultimate recourse. But the West was not wrong in believing that Soviet leaders were committed to a historically driven struggle between two worlds until, ultimately, theirs would triumph. To be sure, other motivations, interests, and objectives played a part, including national aims, institutional interests, and personal psychological considerations. But these influences tended to enhance the ideological framework rather than weaken it.