Trump just expanded his tariff playbook with a powerful trade weapon no president has ever used

President Donald Trump is opening a new chapter in his playbook by invoking a tariff authority that no previous president has ever used — a move that could reshape future trade wars. Trump used a little-known provision of the 1930 Tariff Act to impose 50% tariffs on a range of Canadian goods. Known as Section 338, the nearly century-old law gives the president broad authority to impose duties on imports from countries deemed to discriminate against U.S. commerce. Its first-ever use by a U.S. pre