With multiple layers of tariffs stacking up, some Canadian businesses could end up paying levies of as much as 50 per cent or more as a result of the latest salvos in the trade war. Trade tensions between Canada and the U.S. escalated on Wednesday with the U.S. introducing a 25-per-cent tax on Canadian steel and aluminum imports while a sweeping tariff of the same amount on all Canadian goods is pending until April. Canada is introducing countertariffs on nearly $30-billion worth of aluminum, steel and other U.S. goods. Tom Gould, a customs and tariff strategy consultant based in Seattle,...