smokescreen vs subterfuge

smokescreen

noun
  • Anything used metaphorically to conceal or distract. 

  • Smoke used as a disguise, mask or cover, as of troops in battle. 

subterfuge

noun
  • Deception; misrepresentation of the true nature of an activity. 

  • An indirect or deceptive device or stratagem; a blind. Refers especially to war and diplomatics. 

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