On Monday, Prime Minister Justin Trudeau stepped down as the country and party leader, marking the end of a decade in power. (That’s a long time, but it’s still short of his dad’s 15 cumulative years in office.

The core message is clear: we make things together. Almost two-thirds of Canadian exports to the US and half of US exports to Canada are intermediate inputs in integrated supply chains. Tariffs will reduce GDP and increase consumer prices in both countries. When Canada retaliates on US exports to Canada—as it will—the impacts will be harsher.

By suspending Parliament and promising to resign, the prime minister bought the Liberals time. But Canada will now face Donald J. Trump with a lame duck in charge.