step in vs intervene

step in and intervene both are verbs.

Word	Noun	Adjective	Verb	Adverb
step in	No	No	Yes	No
intervene	No	No	Yes	No

As verbs, step in and intervene are synonyms defined as:

step in and intervene: get involved, so as to alter or hinder an action, or through force or threat of force

Other synonyms of step in include interfere, interpose.

step in (verb)	intervene (verb)
get involved, so as to alter or hinder an action, or through force or threat of force	occur between other event or between certain points of time
act as a substitute	get involved, so as to alter or hinder an action, or through force or threat of force
	be placed or located between other things or extend between spaces and events