United States vs arsenal of democracy

United States

name
  • Federal nation consisting of several states, actual, historical or hypothetical. 

  • The collection of individual states of the United States of America. 

  • Includes the land area, internal waters, territorial sea, and airspace of the United States. 

arsenal of democracy

noun
  • The United States of America, as supplier of extensive materiel support to U.S. allies during World War II; or post-war U.S. as the manufacturer and possessor of the greatest quantity of advanced military weaponry in the world, in the service of defending democratic forms of government. 

How often have the words United States and arsenal of democracy occurred in a corpus of books? (source: Google Ngram Viewer )