How was the Truman Doctrine a change in previous US foreign policy?

A: The Truman Doctrine was a shift from isolationist policy because the belief that it was the US’ responsibility to stop the spread of communism to weaker countries around the world


B: the Truman Doctrine encouraged the US to “speak softly and carry a big stick”


C: The Truman Doctrine aimed to decrease military spending and increase the national surplus


D: The Truman Doctrine encouraged the US to withdraw itself from world affairs and let countries sort out their own differences