Donald Trump and Canadian PM Mark Carney in the Oval Office earlier this month.Donald Trump has called off trade talks with Canada over a controversial advert featuring Ronald Reagan.The US president declared that the negotiations had been “terminated” in yet another online meltdown.Trump took exception to an anti-tariff ad by the government of Ontario featuring an excerpt from a 1987 radio address by Reagan describing the downsides of the levies.In it, the former Republican president says: “High tariffs inevitably lead to retaliation by foreign countries and the triggering of fierce trade wars. Then the worst happens: markets shrink and collapse, businesses and industries shut down, and millions of people lose their jobs.”In the broader speech, however, Reagan also explains why he imposed targeted tariffs on Japanese electronics and his case for utilising them sparingly to address a trade dispute.