neutralisation

(euphemism) the removal of a threat by killing or destroying it (especially in a covert operation or military operation).

Action intended to nullify the effects of some previous action.

A chemical reaction in which an acid and a base interact with the formation of a salt; with strong acids and bases the essential reaction is the combination of hydrogen ions with hydroxyl ions to form water.

Action intended to keep a country politically neutral or exclude it from a possible war.