contend vs go to war

contend

verb
  • To be in opposition; to contest; to dispute; to vie; to quarrel; to fight. 

  • To be in debate; to engage in discussion; to dispute; to argue. 

  • To believe (something is reasonable) and argue (for it); to advocate. 

  • To struggle or exert oneself to obtain or retain possession of, or to defend. 

  • contend with: To try to cope with a difficulty or problem. 

go to war

verb
  • To enter into an armed conflict. 

  • (of a person) To depart, typically from one's home, to join an army at war. 

How often have the words contend and go to war occurred in a corpus of books? (source: Google Ngram Viewer )