Why Canada? America's northern neighbor seems an unlikely target for a trade war

President Trump has escalated a trade spat with Canada — slapping tariffs and banning some Canadian dairy, booze and motorcycles after talks collapsed, and Ottawa hit back with retaliatory tariffs.
The two countries remain tightly linked: Canada sends about 70% of its exports to the U.S. and supplies heavy crude oil needed by Midwestern refineries, plus deeply integrated auto and farm supply chains.
Negotiators say there’s still time to reach a deal (some U.S. bans don’t kick in until Sept. 29), and both sides say they’re open to talks over disputes like dairy, autos and market access.