¶ … consequences of the Truman Doctrine and how it affected other areas of American history. President Harry S. Truman unveiled the Truman Doctrine on March 12, 1947, after the end of World War II, in a speech he gave to Congress. It was a doctrine dedicated to supporting democracy and fighting communism around the world, because Truman felt America had an obligation to others as a leader of the free world. He also believed communism was a real threat and he wanted to make sure that it did not spread outside Europe. The Truman Doctrine had completely good intentions, but experts believe it helped lead to the Cold War and draw up a wall between the United States and the Soviet Union that lasted for decades. In the short-term, many positive aspects of the Truman Doctrine began to be felt. The Marshall Plan, which operated from 1948 through 1952, was an attempt to help rebuild Western Europe, so catastrophically damaged during the war. It also acted as a deterrent to communism, which angered the Soviets. The Truman Doctrine also led directly to the United States offering aid to Turkey and Greece after Great Britain cut off aid to these countries after the war. In Greece, the U.S. gave the Greeks aid to fight communist insurgents, and in Turkey, they gave aid to keep Stalin's forces from taking over the country. The U.S. was afraid the communists would take over the countries, and they wanted to keep them safe from communism, so they handed out aid to gain their support. The Marshall Plan was a direct result of the Truman Doctrine, and most experts considered it a success, since it helped Europe get back on its feet, raise factory production, and begin the rebuilding process.

The doctrine centered on the idea of "containment and deterrence," two ways to manage military build up and might. Containment attempted to keep the Soviet Union contained to the territory they already had, and keep...

Deterrence referred to the deterrence of nuclear weapons, and it grew in importance as the Cold War developed. Eventually, the United States kept a military presence in Europe, and planted anti-nuclear missiles throughout the area in an effort to deter the Soviets from using the weapons in an attack on Europe. Deterrence is still the policy of the U.S. government, and it is being used in connection with attempting to control the nuclear capabilities of Iran and North Korea.
The Truman Doctrine changed American foreign policy in many ways. Through both world wars, America had stayed out of the wars with an isolationist policy that most people supported. The Truman Doctrine changed that. Now, American vowed to be a world leader that openly meddled in other countries and their affairs, and that was a very new and unique position for the country. It changed foreign policy that had really been in effect since the 1823 Monroe Doctrine, which explicitly said that the United States should stay out of European affairs. In fact, the doctrine got its name from the Monroe Doctrine, because members of the press compared Truman's speech to the Monroe Doctrine, so they began calling it the Truman Doctrine. American foreign policy shifted dramatically after Congress approved funding for the president, and it had not shifted in over 100 years.

When the president explained his ideas about American intervention in communism and why it was necessary, he used the "Domino Theory." This theory held that once a country fell to communism, the countries around it would fall like a line of closely spaced "dominoes," and that is one reason the U.S. had to intervene. If they did not, communism would grow to be an even larger world threat, and that could affect every area of the globe. This belief helped justify later American interventions…