Between 2017 and 2021, Donald Trump had the world on a precipice, bracing for his next move, gaming out whether his bluster was a bluff, an overture to a deal or a break with history, as he sowed mayhem to push adversaries off balance.

Trump, who takes office on Jan. 20, said he would impose a 25% tariff on imports from Canada and Mexico until they clamped down on drugs, particularly fentanyl, and migrants crossing the border, in a move that would appear to violate a free-trade deal.

That is the question facing Mexico and Canada after Donald Trump took to social media on November 25th and pledged—for the first time as president-elect of the United States—to impose a 25% tariff on both countries on his first day in power.