On Saturday, 10 October, at a campaign rally in Clarksville, Tennessee, President Trump said that the U.S. and Mexico would come to terms on a new trade deal, and he said Canada does not need to be part of the deal. Trump called the coming agreement with Mexico “great” but gave no details, including when it would be signed, what it would cover, or whether it would officially replace the USMCA. However, for U.S. companies, investors and consumers, it does signal that the rules for North America’s biggest trade flows could be rewritten country by country. Much of Trump’s remarks was aimed at Canada, repeating that the U.S. loses money trading with its northern neighbor and saying that Canada had taken advantage of the...