The correct answer to this open question is the following.
What describes the position that President Truman believed the United States should take when dealing with the spread of totalitarian regimes was the Truman Doctrine or the policy of containment to stop the spread of totalitarianism governments and Communist in other countries.
After the death of President Franklin D. Roosevelt, Harry S. Truman became the 33rd US President from 1945 to 1953. He was the one who ordered to launch the atomic bomb over Hiroshima and Nagasaki, Japan, to end Worl War II. At the end of the war, he did everything that was on his hands to stop the spread of Communism meanwhile the Soviet Union tried to spread its totalitarian ideas in many parts of the world such as in North Korea, North Vietnam, and Cuba.
