US-Canada Trade War Erupts

Full-scale trade war between US and Canada ruptures once-close alliance. Canadian PM Carney declares 'America has changed,' Canada diversifying away from US. Canada rejects US trade deal over unfair demands, vows retaliatory tariffs by Sept 8, sectoral barriers (steel, auto, dairy) deepen rift. Major geopolitical shift with implications for Trump's midterm positioning and world_news.