Final answer:
The Truman Doctrine was a foreign policy initiative instituted by President Truman in 1947. It promised that the United States would assist countries whose governments were in danger of being overthrown by communist forces.
Step-by-step explanation:
The Truman Doctrine was a foreign policy initiative instituted by President Truman in 1947. It promised that the United States would assist countries whose governments were in danger of being overthrown by communist forces. The doctrine aimed to prevent the spread of communism by providing financial aid, military assistance, and other support to these countries.