intervene

verbs

get involved, so as to alter or hinder an action, or through force or threat of force
"Why did the U.S. not intervene earlier in WW II?"
interfere, interpose, intervene, step in
is derived from
intervenor
is derived from
intervention
be placed or located between other things or extend between spaces and events
"This interludes intervenes between the two movements"; "Eight days intervened"
intervene
is a type of (narrower)
be located or situated somewhere; occupy a certain position
lie
occur between other event or between certain points of time
"the war intervened between the birth of her two children"
intervene
is a type of (narrower)
come to pass
"What is happening?"; "The meeting took place off without an incidence"; "Nothing occurred that seemed important"
come about, fall out, go on, hap, happen, occur, pass, pass off, take place