Trade relations between Canada and the USA have deteriorated sharply after Mark Carney suspended negotiations on 22 August, saying that last-minute American demands were unfair and threatened the reliability of any agreement. New US tariffs targeting $28 billion of Canadian goods have subsequently taken effect, with estimates suggesting that 90,000 Canadian jobs could be at risk. Disputed issues include tariffs on automobiles, steel, aluminium and lumber, alongside reported American demands affecting Canadian language and trade policies. Carney, who had previously pursued a conciliatory approach, has now promised dollar-for-dollar retaliation. Other Canadian politicians have proposed measures extending beyond tariffs, including reconsidering American defence contracts. Although the USA has a far larger economy, Canada supplies important commodities including oil, electricity, lumber and aluminium, meaning that retaliation could also increase costs for American consumers and businesses. The dispute marks a significant deterioration in relations between the neighbouring countries and raises questions about their longstanding economic partnership.