: the act of interfering with the outcome or course especially of a condition or process (as to prevent harm or improve functioning)
educational intervention
surgical interventions for cardiovascular disease
b
: the interference of a country in the affairs of another country for the purpose of compelling it to do or forbear doing certain acts
… obscures Eisenhower's decisive personal role in converting the CIA from an intelligence agency into an instrument for American intervention around the world. Arthur M. Schlesinger, Jr.
c
: an occurrence in which a person with a problem (such as a drug addiction) is confronted by a group (as of friends or family members) whose purpose is to compel the person to acknowledge and deal with the problem
stage/mount an intervention
Coaching colleagues and former players pleaded with him to reengage with the game, to no avail, until 1989, when a number of them prepared to stage an intervention. Alexander Wolff