In 1945, the United States and Soviet Union were allies, jointly triumphant in World War II, which ended with total victory for Soviet and American forces over Adolf Hitler's Nazi empire in Europe. Within just a few years, however, wartime allies became mortal enemies, locked in a global struggle—military, political, economic, ideological—to prevail in a new "Cold War."
How did wartime friends so quickly turn into Cold War foes?
Who started the Cold War?
Was it the Soviets, who reneged on their agreements to allow the people of Eastern Europe to determine their own fates by imposing totalitarian rule on territories unlucky enough to fall behind the "Iron Curtain?"
Or was it the Americans, who ignored the Soviets' legitimate security concerns, sought to intimidate the world with the atomic bomb, and pushed relentlessly to expand their own international influence and market dominance?
The tensions that would later grow into Cold War became evident as early as 1943, when the "Big Three" allied leaders—American President Franklin D. Roosevelt, British Prime Minister Winston Churchill, and Soviet Premier Josef Stalin—met in Tehran to coordinate strategy. Poland, which sits in an unfortunate position on the map, squeezed between frequent enemies Russia and Germany, became a topic for heated debate. The Poles, then under German occupation, had not one but two governments-in-exile—one Communist, one anticommunist—hoping to take over the country upon its liberation from the Nazis. Unsurprisingly, the Big Three disagreed over which Polish faction should be allowed to take control after the war, with Stalin backing the Polish Communists while Churchill and Roosevelt insisted the Polish people ought to have the right to choose their own form of government. For Stalin, the Polish question was a matter of the Soviet Union's vital security interests; Germany had invaded Russia through Poland twice since 1914, and more than 20 million Soviet citizens died in World War II. (The Soviets suffered nearly sixty times as many casualties in the war as the Americans did.) Stalin was determined to make sure that such an invasion could never happen again, and insisted that only a Communist Poland, friendly to (and dominated by) the Soviet Union, could serve as a buffer against future aggression from the west. Stalin's security concerns ran smack into Anglo-American values of self-determination, which held that the Poles ought to be allowed to make their own decision over whether or not to become a Soviet satellite.
At Tehran, and at the next major conference of the Big Three at Yalta in 1945, the leaders of the US, UK, and USSR were able to reach a number of important agreements—settling border disputes, creating the United Nations, organizing the postwar occupations of Germany and Japan. But Poland remained a vexing problem. At Yalta, Stalin—insisting that "Poland is a question of life or death for Russia"—was able to win Churchill's and Roosevelt's reluctant acceptance of a Communist-dominated provisional government for Poland. In exchange, Stalin signed on to a vague and toothless "Declaration of Liberated Europe," pledging to assist "the peoples liberated from the dominion of Nazi Germany and the peoples of the former Axis satellite states of Europe to solve by democratic means their pressing political and economic problems." The agreements allowed Churchill and Roosevelt to claim they had defended the principle of self-determination, even though both knew that Poland had effectively been consigned to the Soviet sphere of interest. The provisional Communist government in Poland later held rigged elections (which it, not surprisingly, won), nominally complying with the Declaration of Liberated Europe even though no alternative to Communist rule ever really had a chance in the country.
In the end, the Yalta agreements were not so much a true compromise as a useful (in the short term) misunderstanding among the three leaders. Stalin left happy he had won Anglo-American acceptance of de facto Soviet control of Eastern Europe; Roosevelt and Churchill left happy they had won Stalin's acceptance of the principle of self-determination. But the two parts of the agreement were mutually exclusive; what would happen if the Eastern Europeans sought to self-determine themselves out of the Soviet orbit? Future disputes over the problematic Yalta agreements were not just likely; they were virtually inevitable.
And the likelihood of future conflict only heightened on 12 April 1945, when President Franklin D. Roosevelt unexpectedly died of a brain hemorrhage. Vice President Harry S. Truman—a former Missouri senator with only a high-school education, who had served just 82 days as vice president and had not been part of FDR's inner circle—suddenly became the President of the United States. Truman, who may not have ever known just how much Roosevelt had actually conceded to Stalin at Yalta, viewed the Soviets' later interventions in Eastern Europe as a simple violation of the Yalta agreements, as proof that Stalin was a liar who could never be trusted. Truman quickly staked out a hard-line position, resolving to counter Stalin's apparently insatiable drive for power by blocking any further expansion of the Soviet sphere of influence, anywhere in the world. Under Truman, containment of Communism soon came to dominate American foreign policy. The Cold War was on.
So who started the Cold War?
In the early days of the Cold War itself, American historians would have answered, nearly unanimously, that the Soviets started the Cold War. Josef Stalin was an evil dictator, propelled by an evil Communist ideology to attempt world domination. Appeasement hadn't worked against Hitler, and appeasement wouldn't work against Stalin either. An innocent America had only reluctantly joined the Cold War to defend the Free World from otherwise inevitable totalitarian conquest.
In the 1960s, a new generation of revisionist historians—disillusioned by the Vietnam War and appalled by seemingly endemic government dishonesty—offered a startingly different interpretation. In this revisionist view, Stalin may have been a Machiavellian despot but he was an essentially conservative one; he was more interested in protecting the Soviet Union (and his own power within it) than in dominating the world. Americans erroneously interpreted Stalin's legitimate insistence upon a security buffer in Poland to indicate a desire for global conquest; Americans' subsequent aggressive efforts to contain Soviet influence, to intimidate the Soviets with the atomic bomb, and to pursue American economic interests around the globe were primarily responsible for starting the Cold War.
More recently, a school of historians led by Yale professor John Lewis Gaddis have promoted what they call a "post-revisionist synthesis," incorporating many aspects of the revisionist critique while still insisting that Stalin, as a uniquely powerful and uniquely malevolent historical actor, must bear the greatest responsibility for the Cold War.
In the end, it may be that "Who started the Cold War?" is simply the wrong question to ask. World War II destroyed all other major rivals to American and Soviet power; the US and USSR emerged from the conflict as the only two nations on earth that could hope to propagate their social and political systems on a global scale. Each commanded powerful military forces; each espoused globally expansive ideologies; each feared and distrusted the other. In the end, it may have been more shocking if the two superpowers had not become great rivals and Cold War enemies.