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. Two days after imposing 25% taxes — tariffs — on all imports from Canada and Mexico and threatening to detonate more than $1.3 billion in annual U.S. trade in North America, Trump announced that he was suspending many of the levies on Mexico and some of them on Canada for a month.