The goal of the Truman Doctrine was to:

The Truman Doctrine was an American foreign policy whose stated purpose was to counter Soviet geopolitical expansion during the Cold War. It was announced to Congress by President Harry S. Truman on March 12, 1947, and further developed on July 4, 1948, when he pledged to contain threats in Greece and Turkey.

Explanation:

With the Truman Doctrine, President Harry S. Truman established that the United States would provide political, military and economic assistance to all democratic nations under threat from external or internal authoritarian forces.

The Truman Doctrine was an American foreign policy whose stated purpose was to counter Soviet geopolitical expansion during the Cold War.