Uncle Sam's ugly faces.

The official declaration of the Cold War - The Truman Doctrine.
From history.com

In February 1947, the British government informed the United States that it could no longer furnish the economic and military assistance it had been providing to Greece and Turkey since the end of World War II. The Truman administration believed that both nations were threatened by communism and it jumped at the chance to take a tough stance against the Soviet Union.
On March 12, 1947, Truman appeared before a joint session of Congress to make his case. The world, he declared, faced a choice in the years to come.

The Truman Doctrine was a de facto declaration of the Cold War. Truman's address outlined the broad parameters of U.S. Cold War foreign policy: the Soviet Union was the center of all communist activity and movements throughout the world; communism could attack through outside invasion or internal subversion; and the United States needed to provide military and economic assistance to protect nations from communist aggression.
Not everyone embraced Truman's logic. Some realized that the insurgency in Greece was supported not by the Soviet Union, but by Yugoslavia's Tito, who broke with the Soviet communists within a year. Additionally, the Soviets were not demanding control of the Dardanelles, but only assurances that this strategic waterway would not be used by Russia's enemies-as the Nazis had used it during World War II. And whether U.S. assistance would result in democracy in Greece or Turkey was unclear. Indeed, both nations established repressive right-wing regimes in the years following the Truman Doctrine. Yet, the Truman Doctrine successfully convinced many that the United States was locked in a life-or-death struggle with the Soviet Union, and it set the guidelines for over 40 years of U.S.-Soviet relations.