Throughout the Cold War, the United States engaged in many assertive policies both in America and out of the country, in pursuance to fight communism and the spread of communist ideologies.Encountering new challenges and global responsibilities, the US needed to conserve what it had fought for in WWII. We also needed to contain communist ideas coming from the Soviet Union, without provoking World War III.The United States successfully utilized containment by the application of 3 methods, the Berlin Airlift ,the Truman Doctrine, and the use of naval blockade. The Berlin Airlift was one successful containment method in which, the Untied States responded to the Soviet blockade of Berlin, successfully bringing food and medical supplies to allied controlled areas of Berlin.In June 1948, the Soviets blockaded all exterior access to Berlin. This reprisal was intended to send a sign to the US and its Allies that the Soviet Union did not tolerate western interference in its territories. In response, President Truman made a decision that would allow the US to deliver supplies to the Berlin people without engaging in battle with the Soviet Union. His plan called for American aircrafts to airlift supplies into Berlin. In May of 1949, his plan was promptly accepted, and the Berlin Airlift began flying thousands of food and supplies to Berlin. This dispute proves that the Berlin Airlift was a successful containment method, through the Soviet Unions surrendering the blockade of Berlin. The Truman Doctrine was another successful method of containment in which President Truman declared the US should give military support to countries threatened by the Soviet forces or communist insurgency. In August of 1945, the Soviet Union invaded Korea, suspecting that the Soviet Union would take over the entire peninsula, the United States promptly moved its own soldiers into South Korea. In 1945, the Korea Peninsula was divided between an American, democratic-based government in the south and a Soviet, communist-based government in the north. When North Korean soldiers invaded South Korea in 1950, the Truman administration took advantage of the opportunity to defend a noncommunist government from invasion by communist armed forces. Determined not to allow another country to be defeated by communism, and interested in supporting its anticommunist credentials, the Truman administration decided to provide military support for South Korea. The war continues for several years and finally ends in 1953, very close to the original boarders.The Truman Doctrine was a successful method of containment in which because the Truman administration decided to defend South Korea and its democratic ways, it effectively contained another nation from the communistic ideologies of the Soviet Union. The application of naval blockade preformed by the U.S. was yet another successful method of containment. In January 1959 Cuba becomes a communist country under the reign of Fidel Castro. As of May 1962, the Soviet Union secretly started to move thousands of soldiers, missiles and nuclear war heads to Cuba in intent to bomb America. Kennedy took recognition of the Soviets secret plan and chose to perform a naval blockade to ban the Soviets from bringing in any further military supplies to Cuba. After additional negotiation, Kennedy and Khrushchev agreed on the remove the weapons, and therefore improved relations and moved on, creating peace and avoiding further use of nuclear warfare. The use of naval blockade supported the US policy of containment by keeping the communist Soviet Union from bombing the US. In conclusion it is indisputable that the policy of containment was one of the most important factors in the Cold War. From the declaration of the Truman Doctrine, to America’s support in the Korean war, containment was the driving force behind all of these critical events and decisions. United States successfully utilized containment by the application of 3 methods, the Berlin Airlift ,the Truman Doctrine, and the use of naval blockade.