A week before Donald Trump fired off yet another tariff threat on his neighbors, Justin Trudeau and Claudia Sheinbaum had a chance to confer in person about how to tackle that very scenario. Would they join forces against their errant trading partner or was it going to be a case of every person for themselves?

Threats by President-elect Donald Trump to impose U.S. tariffs on its immediate neighbors appear to have created a split between Canada and Mexico, after Canadian officials said problems with the two countries' borders were not comparable.