When did the Cold War begin?

The Cold War had no precise start date – it is seen as a conflict that gradually originated in the first years after the Second World War. Historians usually point to the year 1947, but there are also other dates proposed, such as 1946 (first significant hostilities between US and USSR) or even 1949 (first atomic bomb in the USSR).


Following the end of the war in Europe, the US and the USSR (or rather: Harry Truman and Joseph Stalin) relations remained allied against the common enemy in the East Asia: Japanese Empire. After atomic bombings, Stalin was still willing to cooperate with Truman, which was for instance materialized in Czechoslovakia, where the Red Army departed from the country and allowed local politicians to develop fairly democratic system.

The first crack in the relations has been visible only in private Truman’s communications, where he mentioned that he is tired of “babysitting” Soviet Union.


This year has seen many events critical for the beginning of the Cold War.

In February, Stalin won sham elections and accompanied it with anti-West speech. In turn, Truman has received tip off about Soviet hostility in the famous Kennan’s long telegram. Just a month later, Churchill spoke about “iron curtain” falling on the Central and Eastern Europe. In a direct response to this speech, Stalin compared Churchill “and his friends” to Hitler.

Europe has seen first political clashes of liberalism and communism in Czechoslovakia – won by communists – and Italy – won by anti-communists – as well as Poland – won by communists year earlier, but confirmed with referendum.

The first military show of force happened in August, when the US sent army and naval forces into the area of Turkish Straits, as their status was contested by the USSR.


1947 is usually seen as the first year of the Cold War due to two significant announcements in the United States.

The first was proclamation of Truman doctrine on March 12, 1947. It announced support to democratic ambitions of all nations around the world. Immediately in 1947, it meant influencing the Greek civil war (waged by communists) and aiding economically Turkey which mobilized its army in response to the Soviet threats.

The second was beginning of Marshall plan (European Recovery Program), which aimed to economically “resuscitate” nations destroyed by the war. After initial ambiguous reception, USSR quickly responded with hostility and prohibited countries in its sphere of influence from participating in the program, offering response in the form of Comecon.


The most important event of 1948 – signalling the Cold War in full swing – was Berlin blockade, in which the USSR attempted to starve West Berlin and force unification of the capital under Soviet administration.


Soviet nuclear bomb program – already started during the second world war – has seen its first successful test on August 29, 1949. Curiously, it was kept in secret and only American detection program uncovered the fact of nuclear detonation.