go to war vs struggle

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. 

struggle

verb
  • To strive, to labour in difficulty, to fight (for or against), to contend. 

  • To strive, or to make efforts, with a twisting, or with contortions of the body. 

noun
  • A contortion of the body in an attempt to escape or to perform a difficult task. 

  • Strife, contention, great effort. 

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