aggression vs belligerence

aggression

noun
  • The act of initiating hostilities or invasion. 

  • Hostile or destructive behavior or actions. 

  • The practice or habit of launching attacks. 

belligerence

noun
  • The state of being belligerent; aggressive inclination to war. 

How often have the words aggression and belligerence occurred in a corpus of books? (source: Google Ngram Viewer )