intervene

Verb

• occur between other event or between certain points of time
  • the war intervened between the birth of her two children
    

• be placed or located between other things or extend between spaces and events
  • This interludes intervenes between the two movements
    
  • Eight days intervened
    

• 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?
    

Related words

• Synonyms: 
  step in , interfere , interpose