Canada says it is 'at war' with US, sets matching tariffs for Sept. 8

Fact-check index: 92/100 — The article's claims are well-supported by the cited sources, with accurate attribution of quotes and reporting to FT, BBC, Washington Times, Toronto Star, NYT, and AP.

• Carney said Canada is now 'at war' with US over trade, per FT — Matches FT headline verbatim: 'Mark Carney says Canada is now "at war" with US over trade'.
• Ottawa confirmed a dollar-for-dollar retaliatory tariff package effective Sept. 8 — Washington Times states Canada is 'threatening a dollar-for-dollar counterattack beginning Sept. 8'; Toronto Star headline confirms tariffs 'to take effect next month.' Article's use of 'confirmed' is slightly stronger than Washington Times' 'threatening,' but Toronto Star framing supports it.
• Carney called Trump's fresh tariffs a 'miscalculation' after negotiations broke down, per BBC — Matches BBC headline: 'Carney calls Trump's fresh tariffs a miscalculation after trade talks collapse'.
• NYT reports the standoff could hurt the US economy itself — Matches NYT headline: 'U.S. Economy Could Feel the Sting From Trade War With Canada'.
• AP frames the rupture as damage to a once-close alliance between the two countries — Matches AP headline: 'A trade war between Canada and the US further ruptures a once-close and durable alliance'.
• Reference to prior 50% tariffs now in force (via linked callout) — Not covered by the provided source material; relies entirely on the article's own earlier reporting, which is outside the scope of these sources to confirm.