The U.S. Court of International Trade struck down the legal foundation of President Donald Trump’s sweeping tariff policy on Thursday, immediately throwing South Korea’s trade negotiations into disarray.

The ruling suspends Washington’s 10% flat tariff on global imports — following a 90-day pause on “reciprocal” tariffs, set to resume on July 9 — and undermines the framework that has defined Trump’s unilateral trade approach, just as Seoul was attempting to finalize a bilateral exemption deal ahead of its own presidential transition.