Answer:
The Truman Doctrine is the principle of the U.S. that they should give support to people and countries that were threatened by the Communist insurrection of Soviet Forces. Truman Doctrine was first expressed in 1947 by President Truman during a speech to Congress seeking aid to Turkey and Greece. Truman Doctrine was seen by Communists as an open declaration of the Cold War.
The reason for the speech was a recent announcement by the British Government that on March 31, it would no longer provide economic and military assistance to the Greek Government in its Civil War against Greek Communist Party.
