dissension vs tug of war

dissension

noun
  • Strong disagreement; a contention or quarrel; discord. 

  • An act of expressing dissent, especially spoken. 

tug of war

noun
  • A dispute between two parties, particularly an entrenched, back-and-forth dispute. 

  • A game or competition in which two teams pull or tug on opposite ends of a rope trying to force the other team over the line which initially marked the middle between the two teams. 

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