Stephen Farnsworth, professor of political science at the University of Mary Washington, said that President Trump has not said which nations will be receiving tariff letters on Monday. Canada may not be on the list of a dozen nations singled out by the president because of recent concessions on trade, or it may be on the list because US-Canada trade has been a priority of the president. “President Trump likes to keep people, and nations, guessing about what he will do next,” Farnsworth said.