A trade war between Canada and the US deepens rupture in what had been a close and durable alliance

For decades, Canada built much of its prosperity on privileged access to the United States. Now, after the collapse of trade talks, one of the world’s closest and most durable alliances has been fundamentally altered, with both countries facing the risk of a full-scale trade war.

Prime Minister Mark Carney acknowledged the break after last-ditch negotiations failed Friday, saying Canada had recognized that “America has changed” and that the countries would “not return to our old relationship.”