containment

(noun) a policy of creating strategic alliances in order to check the expansion of a hostile power or ideology or to force it to negotiate peacefully. Example: "Containment of communist expansion was a central principle of united states' foreign policy from 1947 to the 1975."

(noun) (physics) a system designed to prevent the accidental release of radioactive material from a reactor.

(noun) the act of containing; keeping something from spreading. Examples: "The containment of the aids epidemic." "The containment of the rebellion."