Answer:
Containment Policies: is a geopolitical strategic foreign policy pursued by the United States. The United States policy uses numerous strategies to prevent the spread of communism abroad. A component of the Cold War, this policy was a response to a series of moves by the Soviet Union to enlarge its communist sphere of influence in Eastern Europe, China, Korea, and Vietnam.
The United States policy of non-intervention was maintained throughout most of the nineteenth century. The first significant foreign intervention by the United States was the Spanish-American War, which saw it occupy and control the Philippines. (Non-interventionism) is the diplomatic policy whereby a nation seeks to avoid alliances with other nations in order to avoid being drawn into wars not related to direct territorial self-defense, has had a long history in the United States.
Truman Doctrine: The Truman Doctrine of containment which arose from a speech President Harry S. Truman delivered on 12 March 1947, the country’s reluctance to engage in regional conflicts not directly involving the United States started to change. The country would aid all “free people” being subjugated, starting with financial aid to Greece and Turkey to protect them from communist threats.
Truman proposed that it must be the policy of the U.S. to support free people resisting subjugation from internal and external threats. To help the rest of Western Europe recover from the ravages of war and further the policy of containment.
Marshall Plan: It's a U.S.-led relief package in 1947, it was created the following year after the creation of the Truman Doctrine, it is formally or officially known as the European Recovery Program, a massive initiative to help boost European economies and reconstruct the war-ravaged continent. In June 1948, the Senate, the upper house of the country’s legislative branch, passed a resolution that would change the course of American foreign policy. The Vandenburg Resolution, which allowed the United States to participate constitutionally in a mutual defence system in peacetime.
The Creation of NATO:The countries of Western Europe were amenable to a mutual defense agreement that also included the U.S. and Canada. Secret meetings were held at the Pentagon in March 1948 to negotiate the terms of the trans-Atlantic pact. These meetings led to the formal creation of the North Atlantic Treaty Organization (NATO). Delegates from 12 nations attended a meeting chaired by U.S. representative Theodore Achilles. The treaty was signed on April 4, 1949 to deal with future Soviet aggression against Western Europe. It was the first peacetime military alliance overseen by the United States.
The original members of NATO are U.S, Canada, Belgium, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal and Great Britain.
"BY THIS TREATY, WE ARE NOT ONLY SEEKING TO ESTABLISH FREEDOM FROM AGGRESSION AND FROM THE USE OF FORCE IN THE NORTH ATLANTIC COMMUNITY, BUT WE ARE ALSO ACTIVELY STRIVING TO PROMOTE AND PRESERVE PEACE THROUGHOUT THE WORLD" Harry S. Truman, President of the United States, 24 August 1949 quote after the creation of NATO.