Mark Carney walked away from a proposed arrangement with Donald Trump that would have linked trade concessions to tighter border controls, leaving Ottawa to pursue a harder bargaining line with Washington.
Allies say the decision buys Canada breathing room on sovereignty, but critics warn it raises the risk of punitive tariffs if talks stall before the next G7 meeting.
Carney now faces pressure at home to show voters that independence from Washington will not come at the cost of jobs in Ontario's auto sector or Alberta's energy exports.