Canada imposed ‘dollar-for-dollar’ counter-tariffs on a roughly equivalent amount of US goods. In response, Trump announced that the US would use Section 338 to ban imports of Canadian alcohol, motorcycles and some dairy products starting on 29 September.

Trump has piled on the pressure in recent weeks. He has called on Canadian leaders to ‘fall in line’, ordered that Lake Ontario – which straddles the Canada – US border – be renamed ‘Lake America’, and posted a map depicting the US as encompassing Canada (as well as Mexico, Greenland and Iceland).

Trump and members of his administration appear convinced that Canada will eventually fold under US economic pressure. The imbalance in the relationship might seem to support that calculation.

However, trade wars test not only economic strength but also political resolve – and here Canada may have an advantage. Trump’s trade policies and repeated calls for Canada to become the 51st US state have provoked widespread outrage among Canadians, reinforcing the view that the dispute is about sovereignty as well as trade.

More of this article by Professor Roland Paris at Chatham House