
On this day in 1946, American diplomat George F. Kennan (AKA Mr. X) sent the “Long Telegram” to his colleagues in Washington. Wired from his office at the American Embassy in Moscow, Kennan’s telegram – which was later published as the X Article in Foreign Affairs magazine – was an attempt at warning Washington of Russian aggression in the wake of WWII, and at analyzing Russian motivations and character. Although Russia and the West had been allies in the previous conflict, Kennan argued, Soviet leadership believed that war with the Western democracies was inevitable. Kennan emphasized his point in one line:
[Combating Soviet communism is] undoubtedly [the] greatest task our diplomacy has ever faced and probably [the] greatest it will ever have to face.

American president Harry S. Truman took Kennan’s analysis to heart, and adopted what became known as the containment policy: an effort at undermining Soviet credibility, and preventing the rise of communist states in the areas surrounding the Soviet Union. Although the publication of X Article certainly ramped up tensions between the Soviet Union and her former allies, a number of incidents in the immediate wake of WWII had already soured diplomatic relations between the emergent superpowers:
- Soviet leader Joseph Stalin‘s speech on February 9th, 1946, warning of a looming conflict between communism and capitalism
- US president Harry S. Truman‘s decision to drop atomic bombs on Japan – an act of violence that was interpreted by many in the USSR as a direct warning
- Russian spy Igor Gouzenko‘s public defection to the West after revealing himself as a spy in Canada in September of 1945.
Many historians regard the Cold War as an inevitable clash of two inherently opposed ideologies: capitalism and communism. Although incidents like the publication of X Article certainly worsened tensions, the partitioning of the globe into three separate spheres was already well under way by 1946.