World War II redrew the map of the world, creating vast power vacuums from the defeat of Nazi Germany in Europe and imperial Japan in Asia. Given his own ruthlessness and the lens of Marxist historicism, Stalin could only interpret the Soviet victory as an opportunity both to ensure his nation's security and to promote the inevitable expansion of the communist system. None of the new archival evidence that began emerging in the 1990s has contradicted Stalin's explanation to a group of comrades in 1945 that to the victors would go the spoils; that is, whichever power occupied a liberated European country could be expected to impose his own social system on that state. Stalin heard his allies' pleas for him to pay lip service to a postwar democratic order, best embodied in the Declaration of Liberated Europe issued at the Yalta Conference in February 1945, but at the end of the day this was "algebra," as far as the Soviet dictator was concerned, and he averred a preference for simple math.
Presiding over a vast global empire—though one verging on dissolution rather than expansion—Winston Churchill understood simple math as well. He and Stalin had engaged in just such an exercise in coming to the so-called percentages agreement during a tête-à-tête in Moscow in 1944. Running down the nations of East-Central Europe one by one, the two Allied leaders came to agreement as to which powers would call the shots in the states then being liberated from the Nazis. In effect, Churchill went a long way toward acquiescing in the very division of Europe that he later bitterly decried in his 5 March 1946 "Iron Curtain" address in Fulton, Missouri. Churchill hoped to temper Soviet ambitions, but when it came to the fates of neighboring states such as Poland and Romania, Stalin understood only one language—domination.
U.S.–Soviet relations, vastly improved during the war under Roosevelt, began to deteriorate. Within less than a year after the end of the European war, Cold War declarations emanated from both capitals. In a February 1946 address, Stalin offered up a plateful of Marxist verities, including the warning that conflict between communism and Western imperialism was inevitable and would continue. George F. Kennan, America's foremost Soviet expert, dispatched the "long telegram" from Moscow that same month warning of an unstable, xenophobic, and expansionist regime. The policy Kennan urged in response— "containment" of Russia's "expansive tendencies"—soon became the watchword of American foreign policy. Churchill's address in Fulton, delivered in Truman's presence in his home state, followed on the heels of Kennan's landmark 8,000-word telegram. Stalin responded to Churchill's speech by labeling Britain's wartime leader a "convinced reactionary" and accusing the Western powers of planning a new cordon sanitaire against the Soviet Union.
Rising Cold War tensions focused next on the Near East. Only a showdown in the new United Nations prompted Stalin's grudging withdrawal from neighboring Iran, where the Red Army had remained past an agreed-upon March 1946 deadline. By the spring of 1947, the threat of a leftist triumph in Greece, fear of Soviet influence in Turkey, and the decline of British power in the Mediterranean region combined to give rise to the Truman Doctrine. In a speech that has long been interpreted as an American declaration of cold war, Truman averred in April 1947 that the world had become divided between "alternative ways of life" and that "it must be the policy of the United States to support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures."
Despite its own history of often bellicose national expansion (such as the Mexican War or annexation of the Philippines), the United States would not accommodate itself to postwar Soviet expansion. Washington dominated postwar Japan and western Europe, both of which were reoriented along Western lines, and established a system of military bases across the world. The United States built and controlled the Panama Canal and backed British and French control of the Suez Canal, yet it rejected Soviet efforts to extend influence over the Black Sea straits. In addition to resenting these double standards, Stalin and his comrades feared America's ability to wield its unprecedented economic clout.