Containment

[kuh n-teyn-muh nt] /kənˈteɪn mənt/

noun
1.
the act or condition of .
2.
an act or policy of restricting the territorial growth or ideological influence of another, especially a hostile nation.
3.
(in a nuclear power plant) an enclosure completely surrounding a nuclear reactor, designed to prevent the release of radioactive material in the event of an accident.
/kənˈteɪnmənt/
noun
1.
the act or condition of containing, esp of restraining the ideological or political power of a hostile country or the operations of a hostile military force
2.
(from 1947 to the mid-1970s) a principle of US foreign policy that sought to prevent the expansion of Communist power
3.
(physics) Also called confinement. the process of preventing the plasma in a controlled thermonuclear reactor from reaching the walls of the reaction vessel, usually by confining it within a configuration of magnetic fields See magnetic bottle
n.

1650s, “action or fact of containing,” from contain + -ment. As an international policy of the West vs. the Soviet Union, recorded from 1947.

A policy aimed at controlling the spread of communism around the world, developed in the administration of President Harry S. Truman. The formation of the North Atlantic Treaty Organization (NATO) in 1949 was an important step in the development of containment.