"Continental energy security" was the watchword of both governments and industry for much of the past quarter century in North America: the idea that by linking the U.S. and Canada in a tight web of pipelines and refineries,

U.S. President Donald Trump’s pledge to levy punishing new tariffs on Canada has prompted calls for Ottawa and the provinces to turn to other markets. But any bid to do more business with Canada’s second-largest trading partner,

Justin Trudeau says Canada is ready to respond with counter-tariffs against the US if President-elect Donald Trump follows through on his threat to begin a trade war in North America.