Ideology is a central element in coming to grips with the Cold War. In this respect, the Cold War actually began in 1917, with the triumph of the Bolshevik communist revolutionaries in Russia. The Bolsheviks, led by Vladimir Ilich Lenin, a committed Marxist revolutionary, denounced capitalism as an exploitative and moribund social system. Lenin's contribution to Marxism was his theory that imperialism was the last gasp of capitalism. The Bolsheviks believed that the bloodletting then under way in World War I reflected the penultimate crisis of modern capitalism. Lenin and other communists sought to build socialism in Russia while doing what they could to facilitate expansion of Marxism-Leninism abroad.
The West greeted the Bolshevik Revolution with implacable hostility, including an ill-fated Allied intervention against the Bolsheviks in the Russian civil war, which the Marxists eventually won. The Western worldview was capably represented in the rhetoric of President Woodrow Wilson, who had called for U.S. intervention in World War I to make the world "safe for democracy." Wilson spoke not just for constitutional government but also for free-trade capitalism as well. Bolshevism, with its emphasis on state economic planning, was anathema to the deep-seated faith in free enterprise, a cornerstone of American ideology. Moreover, Wilson, like millions of Americans deeply religious, found Marxist atheism, which had condemned religion as the "opiate of the masses," profoundly offensive.
Hence, an ideological gulf between the Soviet Union and the United States, between communism and capitalism, emerged from World War I and divided East and West throughout the interwar period. Beginning in 1929 the Soviet Union came under the iron authority of Joseph Stalin, a pitiless autocrat responsible for the deaths of millions of his own countrymen in purges, forced agricultural collectivization, and breakneck industrialization. Washington declined to accord formal diplomatic recognition of the Soviet Union until 1933. Among other consequences, East-West hostility ensured that efforts to forge an antifascist alliance against Nazi Germany during the late 1930s would come to grief. When the Western powers rejected Soviet overtures for an alliance against the Nazis, Stalin negotiated his own pact with Adolf Hitler in 1939, paving the way for World War II. After sacking much of Europe, Hitler turned on the Soviets, long his primary target, in an invasion of Russia launched on 22 June 1941. The West quickly embraced the Soviet cause as its own in a mutual conflict against Nazi aggression.
Clearly the wartime Grand Alliance, forged by the Nazi bid to dominate Europe, was little more than a marriage of convenience. Indeed, nothing less than Hitler's bid to dominate Europe could have brought Stalin and the Soviet Union into alliance with Great Britain and the United States. Winston Churchill's memorable comment that he would ally with "the devil himself" against the Nazi regime was no mere quip; Churchill was explaining just how extraordinary the prime minister himself considered the unlikely alliance between East and West. Equally cosmopolitan, but markedly less anti-Soviet than Churchill, President Franklin D. Roosevelt saw the war as an opportunity not only to defeat Nazi aggression but to create a framework through Soviet-American cooperation for something like the world order Wilson had envisioned all too prematurely during the previous European war.
Roosevelt came to understand, however, in the weeks before his death on 12 April 1945, that his vision might not stand up to the hard realities embodied in a renascent Stalinist Russia. Once seemingly on the brink of destruction, the Soviet Union had turned the battle at Stalingrad in the winter of 1942–1943 and never looked back. Despite the unparalleled destruction of the Soviet state, including some 27 million dead in the war, the Red Army found itself ensconced in the heart of Europe, all with the blessing of its wartime allies. The onetime pariah state now stood poised to exert unprecedented influence on the postwar world.