intervene, step in, interfere, interpose -- (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?")
intervene -- (be placed or located between other things or extend between spaces and events; "This interludes intervenes between the two movements"; "Eight days intervened")
intervene -- (occur between other event or between certain points of time; "the war intervened between the birth of her two children")