What was Truman’s response when communism began spreading beyond the Soviet-run Eastern Europe?

Truman responded by implementing the policy of containment, which aimed to prevent the spread of communism to other parts of the world. This policy was outlined in the Truman Doctrine, which provided military and economic aid to countries threatened by communist expansion. Additionally, Truman also supported the formation of NATO (North Atlantic Treaty Organization) in 1949 to create a collective defense against the spread of communism.