সঠিক উত্তর হচ্ছে: Containment Doctrine
ব্যাখ্যা: Containment, strategic foreign policy pursued by the United States in the late 1940s and the early 1950s in order to check the expansionist policy of the Soviet Union. In an anonymous article in the July 1947 issue of Foreign Affairs, George F. Kennan, diplomat and U.S. State Department adviser on Soviet affairs, suggested a “long-term, patient but firm and vigilant containment of Russian expansive tendencies” in the hope that the regime would mellow or collapse. The Truman Doctrine of 1947, with its guarantee of immediate economic and military aid to Greece and Turkey, was an initial application of the policy of containment.
Source: britannica.com