President Harry S. Truman delivered a speech to Congress, declaring that the US would provide political, military, and economic assistance to all democratic nations under threat from external or internal authoritarian forces. This speech was a response to crises in Greece and Turkey, where communist movements threatened to take over the governments.

The Truman Doctrine was the first official articulation of the containment policy, aimed at stopping the spread of communism. By providing aid to Greece and Turkey, the US aimed to prevent these countries from falling into the Soviet sphere of influence.

The Marshall Plan aimed to prevent the spread of communism by stabilizing the economies of Western Europe, making them less susceptible to communist influence and uprisings.

The Berlin Airlift was a direct response to Soviet attempts to force the Western Allies out of Berlin. By sustaining West Berlin, the US and its allies maintained a foothold in the city and demonstrated their commitment to resisting Soviet pressure and containing communism.

NATO was a strategic effort to deter Soviet aggression and expansion. The alliance meant that an attack on one member was considered an attack on all, thus providing a united front against potential Soviet expansion into Western Europe.