Prime Minister Justin Trudeau speaks at the General Motors CAMI production plant in Ingersoll, Ont., on Dec. 5, 2022.Nicole Osborne/The Canadian Press Friends, partners, allies – and rivals. With cross-border auto tensions now in the rear-view mirror, Prime Minister Justin Trudeau is talking about Canada’s next big bilateral challenge: head-to-head economic competition with the United States. From a Canadian perspective, the first two years of President Joe Biden’s term were all about countering a persistent bout of U.S. protectionism by preaching the virtues of trade between like-minded partners. Something sank in. Biden’s panic-inducing plan to energize electric-vehicle sales brought Canada...