Trump's erratic trade policies are baffling businesses, threatening investment and economic growth

Marc Rosenberg, founder and CEO of The Edge Desk in Deerfield, Illinois is getting ready to introduce a fancy ergonomic chair designed to reduce customers’ back pain and boost their productivity. There’s a reason for his caution: President Donald Trump’s ever-changing, on-again, off-again tariff war with America’s three biggest trading partners – Mexico, Canada and China. On Wednesday, the mercurial president once again changed course: A day after he imposed 25% taxes – tariffs – on all imports from Canada and Mexico, he backpedaled and exempted autos crossing America’s northern and southern borders.