iron fist vs totalitarianism

iron fist

noun
  • Ruthless and usually unrestricted control. 

  • Symbol of an army's tank or cavalry branch. 

totalitarianism

noun
  • A system of government in which the people have virtually no authority and the state wields absolute control, for example, a dictatorship. 

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