The U.S. Supreme Court will hear arguments in November on the legality of former President Trump’s global tariffs, imposed under the International Emergency Economic Powers Act (IEEPA). Lower courts previously ruled that Trump exceeded his authority, since the power to levy tariffs belongs to Congress. The case represents the biggest test yet of Trump’s presidential authority and could force the U.S. to refund billions in tariffs. Trump justified the levies—ranging from 10% to 50% on multiple trading partners, by citing trade imbalances as a national security threat. If the Court rules against him, existing trade deals and ongoing negotiations could be disrupted, though his tariffs on steel, aluminum, and cars under a different law would remain unaffected.
It’s necessary to consider that if the Supreme Court sides with the lower courts, the already negotiated deals with the UK and Japan could go into chaos. After the announcement, Trump stated on Truth Social that “that his administration and India were “continuing negotiations” on trade. “I feel certain that there will be no difficulty in coming to a successful conclusion,” he said.” (Kaye, 2025).
Yet tariffs on aluminum, steel and cars were imposed by another law, meaning that they will not be affected by the Supreme Court’s decision.