Tornado touched down near Elkhorn, Man., on Sunday: Environment Canada

A U.S. withdrawal from the Canada-United-States-Mexico trade agreement (CUSMA) would have a “severe but not cataclysmic impact on Canada’s overall economy, although perhaps cataclysmic for some sectors,” according to a new report released this week by Deloitte Canada. The report is titled “Tariffs: A rough road leads to new destinations,” and imagines two broad scenarios in the near future. In the first, the “CUSMA Withdrawal Scenario,” the U.S. opts out of CUSMA entirely. “Trade resets at Most-Favoured-Nation rates that apply to member countries in the World Trade Organization,” the...