(an instance of) defecting , e.g. to another political party (or its leader), to another religion etc

abandonment

the unpleasant feeling caused by the nearness or possibility of danger or evil

alarm, apprehension

acceptance of another's power or authority; obedience; a theory of suggestion

compliance

the act, result, of being treacherous

disloyalty, dishonesty

infidelity

infidelity