The global trade war entered a more perilous chapter when President Trump announced a 15% tariff on all US imports, escalating from the 10% rate that the Supreme Court had just ruled unconstitutional. The announcement, made on Truth Social, drew on a little-known provision of a 1974 trade law — signaling that Trump was prepared to exhaust every available legal tool to maintain his tariff regime.
Section 122 of the Trade Act of 1974 gives the president authority to impose tariffs of up to 15% for 150 days. It had never been used before Trump reached for it in the hours following the court’s ruling. The administration framed the 150-day window as a period of transition during which it would develop new and legally durable tariff tools, allowing Trump’s broader trade policy vision to continue uninterrupted.
The announcement triggered immediate diplomatic responses. Germany’s Chancellor Merz pledged to travel to Washington with a unified European position, while warning that constant tariff uncertainty was acting like “poison” in the bloodstream of transatlantic economic relations. France’s Macron was more pointed, using the moment to underline the value of judicial checks on power — a message directed squarely at Trump’s attacks on the Supreme Court.
Countries that had reached tariff agreements with the US found themselves in uncertain territory. The UK, which thought it had a 10% deal in place, now faced a higher rate and fresh questions about the reliability of any agreement made with the current administration. British business associations warned of severe consequences for trade relationships and economic growth on both continents.
Trump’s response to the Supreme Court ruling was as much personal as it was political. He attacked the majority justices by name, called some a “disgrace to the nation,” and reserved particular venom for his own nominees who sided with the majority. With US businesses and consumers absorbing an estimated 90% of tariff costs and top trade associations calling for refunds, the political calculus of Trump’s aggressive trade stance grows increasingly complicated.