In the long arc of North American economic integration, few moments reveal the fragility of interdependence as sharply as a government threatening to expel a company that already employs thousands of its own citizens. President Trump's ultimatum to Bombardier — build in America or lose the American market — arrives as US-Canada trade relations reach a breaking point, with 50% tariffs imposed and billions in retaliatory measures imminent. The demand places a Montreal-based aerospace giant, already deeply woven into the American industrial fabric, at the center of a dispute that is less about ma