The Globe and Mail reports in its Saturday edition that the auto sector in Southwestern Ontario faces big challenges thanks to a threatened trade war. The Globe's Adam Radwanski writes that sector businesses are on edge, anticipating an industry shutdown if a 25-per-cent tariff on Canadian and Mexican imports is implemented. Despite a one-month tariff deferral, solutions for how to respond are in shorter supply than for other Canadian industries. Parts-sector leaders acknowledge that if tariffs are imposed, some companies may not survive and others might need to move operations to the U.S. With about 80 per cent of their sales tied to the U.S., domestic resiliency-building measures are an uneasy fit at best. That includes, for example, knocking down interprovincial trade barriers, which currently tops the list of near-term strategic options being touted by both the government and the private sector. No other province in Canada has an auto sector capable of partially replacing the U.S. market for vehicles or assembly-line components produced in Ontario, nor is there any serious discussion about such a development emerging. Turning away from the U.S. in favour of international export markets is not much more promising.