The Globe and Mail reports in its Monday, Aug. 31, edition that President Donald Trump's threat of a 50-per-cent auto tariff makes it unlikely Canada will be able to maintain an integrated North American automotive market under his administration. The Globe's guest columnist Tom MacDonald writes that on Sunday Mr. Trump posted on social media, "I don't want Canadian cars, I don't want Canadian parts, I don't want Canadian anything." Mr. Trump does not believe in win-win arrangements. He is happy to inflict economic losses on his own country as long as he thinks that he is inflicting greater losses on a trading partner. Honda said on Wednesday it would not build another North American plant without an extension of the United States-Mexico-Canada Agreement. Last Monday, shares of major Canadian auto-parts companies fell as much as 9.7 per cent on the collapse of trade talks. For Canada, the moment is dire. If the integrated North American auto market unravels, the fallout compounds and will spread across the wider economy. To prevent trade diversion from U.S. tariffs and support domestic auto manufacturing, Canada should implement a 25-per-cent global tariff on all vehicle imports.