The Globe and Mail reports in its Wednesday edition that President Donald Trump's pique over Ontario Premier Doug Ford's Reagan commercial reminds us that he would likely scuttle any agreement between Canada and the United States if he felt doing so would serve his purpose. A Globe editorial says the planned review of USMCA, slated for 2026, could see further disruptions from Mr. Trump. Ottawa must do everything in its power, short of compromising sovereignty, to reduce or eliminate sectoral tariffs. If a deal cannot be reached, Ottawa and Canadians need to be prepared, not just for potential failures in U.S. negotiations, but to strengthen the chances of securing an arrangement. Canada's best alternative in talks with the Trump administration may involve tariffs on most goods, with reduced rates for crucial items. This would lead to a contraction in manufacturing, particularly in the auto sector, resulting in lower economic growth for years as the economy adjusts. Prime Minister Mark Carney has been working to secure new markets for Canadian exports, but this is a long-term solution. If we return to the trading relationship before the 1988 free-trade agreement and the 1965 auto pact, our economy will suffer.