Trump's 50% tariffs on Canadian goods take effect after talks collapse

President Donald Trump's 50% tariffs on Canadian goods took effect Saturday after trade negotiations collapsed, affecting approximately $20 billion in imports ranging from hockey sticks to agricultural products. Canada's Prime Minister Mark Carney promised "dollar for dollar" retaliatory measures starting Sept. 8, targeting steel, dairy, appliances, and electronics. No further talks are scheduled, deepening the trade war between the two nations. The tariffs use a never-before-invoked 1930 law requiring no investigation, and experts warn costs will trickle down to consumers. Legal challenges are expected, with broader economic and political implications looming.