It is not the economic impact of tariffs that is most worrying

Canada’s business press remained sanguine. Belligerent statements by the American president, one Toronto-based newspaper wrote, were mere campaign rhetoric; he would ultimately decide against tariffs that might “arouse resentment in Canada”. Such confidence turned out to be gravely misplaced. In 1930 Herbert Hoover signed into law the infamous Smoot-Hawley tariffs, named after their congressional sponsors. The average levy on American imports increased from 40% in 1929 to 60% by 1932, and the global trade system unravelled.