General Motors warned Friday that President Trump’s threatened tariffs on imported vehicles could lead to “a smaller GM,” isolate US businesses from the global marketplace and cause job losses. “Increased import tariffs could lead to a smaller GM, a reduced presence at home and abroad for this iconic American company, and risk less — not more — US jobs,” the Detroit-based automaker said in comments filed with the Commerce Department, The Street reported. “Combined with the other trade actions currently being pursued by the US Government — namely the Section 232 Steel and Aluminum tariffs and the Section 301 tariffs...